1)... much cleaner, as well as non corrosive
2)... as little as 0.5 up to... ( it's a very bulky powder & should not be compressed, so case size & bullet used are max limiting factors )
3)... probably a little slower, but then I've never chonoed Goex or 777
4)... I have 3 loads I load in 32 S&W, pop gun "check out the revolver" loads, use 0.5 grains of TB, & a Hornady soft lead round ball... these work great in any gun that's even remotely safe to shoot... 2nd load uses 0.7 grains of TB, with a light weight cast bullet, these shoot nice, & give me target grade accuracy, though the sights are not target grade
... 3rd load I only use occasionally, & are my carry loads... a bit heavier cast bullet, & as full as I can fill the case, without compressing ( never compress Trailboss )
I collect pocket black powder revolvers, & have around 3 dozen different calibers, makes & models & barrel lengths... BTW... the S&W model 1.5 ( like you have pictured ) is one of my favorites