@Benjamin -- think I follow your attack logic. i have another poker/combat design somewhere sketched out that is more squad-based (like Puzzle & Dragons or Marvel Puzzle Quest) where each character in your party "fires" on different hand combos. Having your attack damage be your attack level minus their defense level wouldn't work as well with this design, because the intention was to keep the randomly generated enemies at roughly the same attack/def. level as the player. That could certainly be redesigned, but as it stand you'd end up with all fights being essentially the same.
Re: Bfxr/labchirp. definitely need to spend a weekend or two familiarizing myself with what's out there. For my non-LD games, I just usually just buy sound effects from Sound Rangers or another site.
Statwise, there are 3 stats for any piece of gear: attack, defense, and initiative.
Attack does what you'd think (sets your base attack value)
Defense is a bit mislabeled, as it's really how much health you have (didn't want to get into the complexity of balancing ATK vs DEF)
Initiative is a bit complicated. When your initiative bar fills up it's your turn to play a hand. The fill rate is tuned to basically be 1 second if your initiative were 100. So if your initiative is 50, you go every 2 seconds. If it's 25, once every 4 seconds. The players right now are hard-coded at 40, which is once every 2.5 seconds. The idea was to have some weapons trade off attack rate for rate of fire. A bow might deal only 4 base damage but get to go every second instead of every 2.5 seconds.