I've been playing SvZ2 since it came out almost everyday, not very long, but just a few multiplayer games here and there. Anyways, here are my suggestions (for iPhone):
1) Once you get the artifacts that upgrade your hero (5%/10%/20% sword/bow damage, 5%/10%/15% armor upgrade) and the horsemen (5%/10%/20% health and damage incresase) I think that percentage should show up where you are looking at the Hero and Horsemen's stats in the Shop. Like my Ronin sword is level 6 doing 40 damage, but i have the 20% sword artifact, so it should show him doing 48 damage. Same goes for the horsemen. I have the 20% health and damage artifact. My Horse Archer is level 6 and currently shows he has 175hp and does 125damage, but really its 20% of that so he really has 210hp and 150damage and that is what should be shown when I look at his stats.
2) When looking at the Riflesmith, Swordsmith, and Horse Master's stats in the shop, I believe it should show exactly what they do to the Archer, Farmers, & Horsearcher/Horseman. Does that increase damage and health, just damage, just health? Is it +20 hp/dmg, +50, +100? Is it 10%, 20%, 50%??? I think knowing this would help the player decide which troops he'd like to use. Knowing the exact stats and what each ally does would be tremendously helpful to each players defense.
3) Rocky T'man does no damage to heroes or to the gate in multiplayer. I think it should do both.
4) When setting your defense for hero/troops in multiplayer. Does it matter the order of the slots you place the troops in? Say I am using the Samurai as my hero, I have 5 troop slots (1)(2)(3)(4)(5). Does the AI randomly summon any troop, is it in order of how they are placed, is summoned from lowest leadership points first (farmers/assassin then Nobunaga last), is it always random, is it highest leadership points first, is it whatever is in the (1) slot, or the (5) slot??? I think this is very important to know because I rely HEAVILY on my samurai being on his stead in battle, I almost have it to level 10 and he is so much more powerful while riding it. I feel it would be stupid if the AI didn't even mount him and just summons a bunch of farmers first, or if it depends on the order that you places your troops in your lineup.
5) The new multiplayer system is great, much better than before, but i believe it can still be improved quite a bit to make it more challenging, because that's what everyone wants! My best defense rating is 1800 right now, but I can dominate players whose defense rating is as high as 3000, but at the same time my AI gets straight up dominated by a player who has a 1100 rating, but, of course, when I go to defended my artifact against that player it is a joke and I just sit at the gate and destroy him and his army.
6) Add a few more daily challenges. Make then harder. Add one with the new hero, Daimyo, so players can test him out and see if they want to purchase him, just like you did with the Sorceress.
7) In single player, I love how before going into battle you can see the enemy's stats. GREAT IDEA! However, once you play through the waves for a 2nd, 3rd, 4th time, the enemy's stats remain the same, but it is 100% clear that isn't true at all, they are much, much stronger. So the stats need to show the actual amount while playing through again.
Those are the suggestions I currently have. I would also like to thank the SvZ2 developers. I'm sure you have a lot on your plate and I thank you for making such a great game! It is the only game I play and I was a huge supporter of SvZ1. So thank you! I hope you take my suggestions to heart as i think some, if not all, will make the game so much more fun to play!
I also welcome comments from other players and there own suggestions or suggestions that would improve mine.