I couldn't read each answer to this Topic because of lack of time, so, if some of my advices have already been given, I'm really sorry, and forgive me.
So, about strategy, you say... I and my girlfriend, Lilith played Ascension for a long time, and we often clashed each other or just played against (of course MAXed) AIs (we played it very much xD), so we can tell we're pretty expert of the game already. We're helping you out as much as we can! :3 (Please trust what I'm saying I know what I'm writing)
- limit myself to 10-12 Mystics & Heavy Infantry total [purchased in an order dictated by the vagaries of the center row]...
Ok, here's the first, sightly problem : Lilith usually gets 2 or 3 of them per play, while I instead get 1 or 2 of both of them when Center Row Cards sucked.
Reasons behind this suggestion : There are many Main Deck cards that cost as much (or, sometimes, they even are more convenient than) as Heavy Infantries and Mystics, and do their same effects (often boosted, though), aside from giving you the same amount or often more than their Honor Points. Cards like these are a must for all kind of decks you're building. Some of them are Deathseeker, Runic Lycanthrope, Kor, the Ferromancer, Spike Vixen, Scrap Scrabbler and so on. I hope you can see the pattern between them. If you didn't, I can explain better what I meant. I know them by heart because I always purchase them during my plays!
- avoid buying 1 rune cards that do not replace themselves [draw a card]...
Hmm... this is a hard point to explain... What I can say for sure is : don't turn your back on them that easly. They mostly are situational (except for Arha Initiate and Wolf Acolyte, two must-have cards (Wolf Acolyte, at least. You could have left Arha Initiate in the Center Row as well, just to let it fill a Center Row space for next player(s), but I'd suggest you to buy it), but they're the most suitable cards to acquire instead of overloading your deck with Mystics and Heavy Infantries.
Reasons behind this suggestion : Aiyana's Messenger, Grease Monk and Skyrocket Drone are good substitutions to Mystic, since they all virtually give you 2 Runes (I said "virtually", because there's a remote chance that they would only be worth 1 Rune instead than 2), while Void Militia is the only, worthy substitution to Heavy Infantry, since they "virtually" both give you 2 Power (same as above). When the Center Row is filled with high-costing cards like Samæl the Fallen, Repurposer, Ender of Days, Assimilation Plant, and no low-costing ones, they're your only cheap lifenet.
You used Arha Initiate as a bad card, but I'm telling you what : no card with the "Draw X card(s)" rule is bad. It virtually tells "transform this card into another one you have in your deck at random unless you know what you have on the top of your deck". It doesn't sound bad, to me.
- prioritize the buying of cards that either draw a card or banish a card in your discard pile or hand or both...
This is just fine! That's what everyone aims for in the very beginning. As long as banishing Void cards like Voidfeeder, Abolisher, Azerax of the Black Watch and similar don't pop up, game goes veeeeeery slow...
I wouldn't suggest you Arha Sensei and Arha Mentor, though, since they only fills your deck with long-term useless Mystics, while I instead reccomend Journeyman Sage for turns 20-. Raj, Psionic Master is instead a must-have. Only a deck with Center Row banishing cards like Seeker of the Forked Path and Wandering Askara can effectively contrast him.
- as soon as possible, start banishing the "red shirts" out of my deck...
Hhmmm....? I suppose you meant Apprentices? In that case, yup!
- trying to keep my deck size between 20 & 25 cards until the late-game honor grab gets underway...
That mostly depends by your deck's drawing efficency. Since Rise of Vigil Expansion came out, I often played with decks composed by 70+ cards in the very end and they all just worked greatly!
Before Energy Shards appeared, my decks often were composed by 15 (!) to 40 cards, according to many variables like Center Row cards acquired during the game, banished cards, opponents' strategies and so on.
Don't limit your deck construction too much, though. Just try to figure out how many cards you potentially can draw each turn, then decide whether to not buy any Heroes anymore or just go all out (I often had problems with my little deck's size sometimes : due to Events and acquired cards, I found myself having 6 cards in the deck, being 1/2 Apprentice(s), (or) a Militia and other banishing cards like Arbiter of the Precipice, Arbiter of Fate and so on at turn 4... definitely the worst situation ever, since I couldn't buy anything but Aiyana's Messenger, Wolf Acolyte & co, but they often came out during other players' turns or just don't pop out when I really need them). It might take some time, at the beginning, to figure it out, but you'll soon find your own limit. ^^
- i generally try to gain my honor through the game in the form of Monsters, so as to not dilute my deck...
The game actually provides players two ways of winning : by defeating Monsters, or by gaining Honor Points by indirect ways (Beacon Shaman, Dandellion Witch, Atrolabe TRX, Beast Staff...) and having many or/and high-valued cards (Assimilation Plant, Adayu, the Chosen, Black Hole...) in the deck. It seems like you belong to the first category, while I instead belong to the second. xD
Not that I don't kill Monsters, to be clear! I just don't focalize my attention on defeating them, rather than getting better cards for the deck.
- Never go for a full-attack deck! Runes can buy anything (75% Center Deck's composed by Artifacts and Heroes), but what if no Monster popped out in the Center Row or they did during opponents' turns and they killed them before you could? Only gaining Honor Points from Cultists during a turn is a dead turn!
- i generally eschew Constructs when possible, until the late-game honor grab commences, at which point i start prioritizing them for
their high rune-to-honor value...
I did, too, during my first plays. I'll never do that anymore!
- Always grab Constructs whenever you can! Don't always prefer them over Heroes, though. It'll depends by compared cards!
Reasons behind this suggestion : Not only Mechana Constructs are the most efficient way of gaining high-valued cards during a game, Constructs also serve you well! You play them, and they stay there forever (until pests like Acidic Crawler, Polaris Demon, Sea Tyrant & co pop out), activating their effects each turn! And many of them really are powerful, too (Black Hole, Beast Staff, Dreamer's Glass...).
- if there is no play that truly benefits me, i try to remember to simply pass the turn and waste the runes, rather than weaken my deck...
That's just right.
- i pay close attention to the order in which i play out my hand, avoiding the "Play All" button as much as possible, to optimize my tactical
play: my mantra is "draw, draw, draw, banish & draw some more..."
This is right, too. Pressing "Play All" during first turns isn't a big deal, but when your deck starts getting sinergy, pressing it would mean a dead turn, under certain circumstances!
I hope I've been of any help! If you have any other question, anything, just ask or send a PM! :3 I'm always glad to help others whenever and however I can!