I can only speak to how I'd like Funeral and Border Wall to play as they are both untested currently.
Funeral (v0.1) - Gazbag summed this one elegently. I imagine during the early game in most cases a player will want to "bury their Copper" under Estates or Shelters. If not, welcome back Coppersmith; you've been missed! Even if this isn't used mid to late game, my hope is that it's a good enough one-shot trasher that people will still pick it up.
Mid to late game, I can't say much that hasn't already been said. Again I can only speculate how this will play. I just hope this entices players to diverge from normal strategies and play with cards that are seldom touched. +1 Card and +1 Action should make any Action fit into any strategy. You just can't rely on the bonus being around forever, unless you get the last Funeral play off.
So the hope is that funeral is very powerful with calculated play and a disaster for those who just buy a bunch of bridges and try to get a cantrip effect on them. Of course playtesting is needed!
Border Wall (v0.3) - Asper is correct that an Attack type shouldn't be too hard to resolve. Beyond that, there isn't much I can say about this card. It's a bit beyond my reasoning ability and may end up being unbalanceable, but I thought it was an interesting enough concept to share and get thoughts on. I'll try and get some playtesting in soon.
Commanders - I get the elegance of implying one passive effect with something there's only one of, a top discard pile card. But how reliable can it be in practice? Basically, I'm raising the thought: why aren't these using their own mat? Since you have multiple Commanders you seem to want to enable switching between different 'command modes' when there is more than one in a kingdom, and a mat would make this simpler, even if it is adding more components.
That Risen King giving a global effect on trash is well discussed. I firstly wonder when you'd choose to trash one and get an advantage out of it for yourself, and secondly if there is more than one in the trash, I think you'd gain a card per copy in the trash?
Commanders - A mat would be elegant, but playing from the discard opens up a lot of interactions with discarding cards and mid-turn gainers. The absence or inclusion of these cards will say a lot about how reliable Commanders will be. I'm also trying to implement various levels of reliability into each Commander. Marshal only hurts your hand when played, but it allows you to put another Commander in your discard, which I think should be quiet powerful. Osho has no reliability built in, but is very cheap. Risen King has some mid-turn gaining abilities and as you mentioned, has a global impact from the trash. And yes, multiple Risen Kings in the trash means multiple cards gained off of trashing. I haven't revealed General yet (the 4th Commander), but it's Commander effect will apply while in play and while in the discard, so it will be very reliable, but very expensive.
Honestly though, you raise some good questions. The Commander concept is all hypothetical at this point, but play-testing will come soon enough. As always, thanks for your thoughtful analysis Aquila! I really like some of your cards and will soon try my hand at returning the analysis favor, but be warned, my card analysis skills are sub par!