Any question answered...

Same as @ectoplasmosis says... buying inside a matched solvent family is much more reliable.

For the decals being compromised, best practice is to buy more decals than you need and test one first by spraying directly on it. Some are paper and the porous fibres can absorb the solvents go pickley. Some are thin vinyl and they just melt. Some have adhesive on the top, some on the bottom, and this reacts badly with the paint. All things which can go wonky when introduced to paint solvents... the worst time to find this out is a the clear coat stage.

One final bit of unsolicited advice which I hope is helpful rather then condescending relates to the clear coat. Done properly, a non-gloss finish should be applied over a clean gloss finish. Broadly speaking, matte/satins/gloss often have the exact same ingredients, only in different quantities... a matte finish will often have more of the drying/accelerant ingredient in it. This makes it initially cure faster so the clear forms in a haze rather than being allowed to flow and make that glassy gloss sheen. As a result, non-glosses aren't as strong as gloss. Non-gloss products land wet and shiny so you can't see the end result mid-process - people tend to under or over apply in order to compensate. Non-gloss finishes mostly can't be polished or de-nibbed either so once they're scuffed, they're always scuffed. As a result, matte and satin finishes need a much more skilled application and aftercare. Best practice sees you do a full gloss clear over the bike and the sticker kit, then gently abrade it a little to get your surface perfect, then get the matte/satin on top. This will also help you get the edges of the decal kit smoother and flatter too.