Black powder in an 1872 conversion

Black powder is loaded to fill the chamber, in a manner that loading the bullet slightly crushes it. IMHO your gun will work with a BP round so charged.
You can download but the empty space needs a filler material.
Opentops such as the 1872 should not be fired with souped-up rounds. Use cowboy loads if you want lighter rounds.

Since you're loading 2F it should be just fine. I would think even 3F would be okay. You might get a bit slower/less power with your 2F loads but that's fine with those open-top style revolvers.

I would think that 2Fg would be more suitable for a rifle/carbine as they have a longer barrel and more time for the larger 2Fg granules to burn. I use 3Fg in .45 Colt on up to 40 grains which needs a drop tube and a compression die to get it in. 32 grains sounds like a good load though but make sure it's enough to crunch down by the bullet. And really .45 Colt is supposed to be the cutoff point between 2Fg and 3Fg so either works but was referring to 3Fg as being more efficient in a short barrel.

3F is better for pistols, but it won't matter much unless you are after a personal defense load and want maximum velocity or are after fine tuning a target load. You will likely be surprised at how boomtastic a 32/250 load is ;-)

Again, for S&G, the bullet you are using is fine, but for better accuracy, a bullet in the 8-10 BHN range will obturate better over black powder, and sizing to .002" over groove depth will also help.

No amount of 2F or 3F BP that you can pack into a 45 Colt case will do any harm to your pistol. But after hoots shooting that load, you may want to try 25 grs with a cornmeal filler. Still lots of sound and fury, and with the right bullet, plenty of accuracy, but less boomtastic.

I use 36 grains in 44-40 and 45 colt rounds. Usually 2f for regular shooting or CAS. 3f for higher velocity hunting or long range side matches etc.

I would suggest
https://www.thehighroad.org/index.php?threads/shooting-black-powder-in-cartridge-guns.821193/