Not many queens get paid to perform so they earn their money from tips. If you like a queen (whether it was because of her outfit, her performance, or the song that she chose), you have the option to tip them. Normally, you can go as low as $1.00 per queen or higher if they performed really well. Since most likely a multiple of them will perform, I suggest you break a $50 into $1 singles, 5s or 10s(if you're feeling really generous).
It's not something you have to do but if you feel they earned it, go up to them and they will simply take it. Don't expect them to say thank you since I've been told it's tacky for them to stop in the middle of their lip sync to do it. Some might smile/wink/hug you/blow you a kiss as gratitude but it's up to them.
It's fine. I haven't done full on, dressed up and made up drag yet. Only been practicing my makeup. Seeing as I'm a noob, it takes me forever to get it done (2-3 hours). Imagine if I covered all my bases: hair, makeup, clothes, legs and nails. It'd take me half a day. LOL After I'm done with my makeup I leave it on for a couple hours. 8 make up removal wipes later, I'm happily back to being myself.