IMO, for pistol it's hard to beat Universal Clays or 231 (HP-38).
Agree.
I would skip Unique and try for Universal it is cleaner and meters better. (some people swear by Unique though)
Nothing wrong with Titegoup you just need to be careful as the charges don't take up much space. (less of a concern in .380 than .45 colt, Note: you always need to be careful no matter what powder you are using)
Think of it as the difference between a 1/10 and 1/12 of a full glass vs 1/3 or 1/2 of a full glass. (or a glass that overflows) Just easy to spot things with bulkier powders.
Titegroup is a "fast" burn speed powder and tends to be less forgiving than some others. Titegroup is not what I would recommend for a beginner but no reason you can't use and it won't work (maybe well) for you.
There are very few pistol/shotgun powders you can't use in one of the calibers you listed.
Some may work better than others for a given caliber/bullet/charge weight/pistol, but most will work fairly well. Exceptions are things at the very slow side of pistol/shotgun powders.
Unless you want to pay the hazmat you use what you can find locally. If you do want to order something it helps if you order primers along with the powder.
Even in small quantities the cost savings can sometime make it worth the fee+shipping.
For example order 1lb powder $20, 2000 primers $40
LGS 1lb powder $27, 2000 primers $60.
So order =$60, LGS =$87 Hazmat = say $28+ normal shipping say $7 so total shipped $95 or only $7 more than at the LGS. (I do purchase from my LGS on occasion if they have what I want)
Make it 2lbs of powder or 3000 primers and you are even or ahead.
(I know 3000 primers may sound like a lot but when you can load for $6 or $7 a box you can shoot twice as much ammo for the same price
)
Most likely you will find each caliber has a preference for its own flavor of powder. Some may agree with each other.
I have multiple 9mm pistols, what works well in one generally works well in the others but they each have a different of idea what works best. (2 of them actually seem to agree)