Stephen there are no hard and fast answers to most of your queries...
Best advice: Hire a competent experienced MUA...
Where to find?
https://www.weddingwire.com/wedding-beauty-healthInvest some quality time on this site... it holds the answers to many your questions.
Ok, Time in prep? Depends on the client...
Bridal gets the most time... sometimes over an hour (or more if airbrush is requested)
Photoshoots? 40 minutes max is an industry standard... a competent MUA can accomplish a clean beauty look in 20 minute.
If I've already worked with the talent before it moves quickly...
btw, I always do a "Bridal Look" trial session, so no last minute surprises,,,
As for glitter, avoid it... it's a mess... and dangerous if you use inappropriate product.
My biggest challenge? Covering Ink on Brides (Countless brides all say the same thing) "why was I so stupid to get those tattoos"
"Touch-ups" on set? be careful negotiating with a professional MUA... staying for touch-ups during an event is a pricey "extra".
As a photo assistant I've done lighting for lot's of commercial shooters in my market for Corporate Head shots... The story is always the same... Matte Blotting Paper (hand them a half dozen sheets and send them to the "Powder Room" just before their turn on set.
My fav blotting paper (from Japan) has been on back order for ever (pandemic related?)
Here is an alternative...
https://www.amazon.com/gp/product/B005JRT7A8/You should always have lots of this available when ever you are photographing people.
For my bridal clients I give the MOA (maid of honor) a little "rescue" pack with a pack of powdered rice blotting paper... put her in charge of keep the bride sheen free...
As for powder? Unless you know what you are purchasing avoid...
Talc so widely used is a very serious carcinogen. I use only corn starch based powder now...
https://www.fda.gov/cosmetics/cosmetic-ingredients/talc As Bobby Dylan said... "look out kid, they keep in all hid"
btw, those are "real" lashes... I curled them first then applied black mascara...
Don't even think of doing this...
I hold a cosmetology license from the state of Maryland...
Many months of training... $2K and the lions share of students were estheticians...
Once again, hire a professional bridal makeup artist...
They can and likely will take your beauty genre work entirely to the next level...
All the best on your journey Stephen