"Personally, I don't see the point to "always peace" being in a war game, but I guess someone else did." one of my most fun/suspenseful games was in always peace, with only domination victory enabled. i had to gain lots of land tile flips (some city flips but they weren't actually necessary) to win, and couldn't take any by war. it was challenging in a completely different way and lots of fun for me. i have always been the type to think in SP that it's your game, play how you want and ignore (no offense meant to any of) the "so-and-so isn't a real victory" types. the game is designed to appeal to different folks in different ways and that's a great thing, it doesn't limit anybody it just adds more options, i <3 that.
back on real topic:
i agree with most that half-price castles are a waste. they go obsolete way too early and aren't that useful even during their lifespan.
"How about allowing Protective Gunpowder units have the ability to have Drill Promotions. If Protective gunpowder units can have Drill Promotions beyond Drill1 it would make more sense."
i've seen that in action in a back-door way and it might be overpowered. for hubby's first game using Warlords, he picked Toku, he wanted to try out the agg/pro combo and liked the idea of the UU with those traits and the UB (it had never dawned on me until that game that the shale plant provides power, as in even if you don't have coal, nifty even not counting the +10% hammers). i was cyrus, with immortals. we did lots of barb farming early on for exp.
granted, this experience was on a MP team game, and at a low level (warlord i think) since it was his first. so we had many advantages that don't usually apply (lots of money to share, so we were able to upgrade a lot of promoted vets which can be really really powerful, we were able to mostly split military duties--he led the foot soldiers, i was the royal canadian yaksman division). so if you want to skip this since it is clearly atypical, feel free.
we rocked. hardcore. he got to drill4 on a lot of early units, and kept them around to upgrade to riflemen/infantry later (the game didn't last to mob inf or tanks). he ended up using quite a few offensively on opponents--even the ones we didn't have a military-tech advantage on it was a slaughterfest. and i'd made some medic units early on, boy howdy even if the enemy suicided cats/trebs/you name it on our SODs in the field, hubby's troops would start next turn barely scratched, ready to go. he used his first GG on a drill4 samurai or something and then went up the CR line, he wanted to see how that worked out and that guy was a killing machine. our combined combined forces were amazing.
drill4 is amazing, and can be used offensively in the right circumstances (we had better circumstances than most, of course). the getting to drill4, and keeping those units around to upgrade them to CR later is the challenge, and probably impossible in real person vs. person MP (which i haven't tried). but when you can do it, you'll be impressed. everybody knows that drill4 is far better than drill3, but not everybody has seen it in action, particularly offensively, and i assure you it's impressive.
just sharing a unique perspective, admittedly in hard to achieve normally circumstances.