Building OAK cage! some questions on tile floor and building

So I decided to build Draco a 4x2x2 oak cage. I used 3/4 oak plywood for the box and solid oak trim for the frame the glass will be attached to. I just have a few questions for those of you with wooden cages! The door plan is the whole front will hinge upward so I have plenty of room to pick him up and clean!
I also plan to mount the lights inside the cage on the roof with his uvb light fixture and basking light fixture on one side and his CHE on the other for night time.

I also made a built in sand box for 1/4 of the floor of the cage with an Oak 2x2 board so he/she can dig a little whenever desired!

1: I'm sealing the inside of the cage with polycrilic water based sealant...should that be fine?

2: What should I seal all the edges inside the tank with? 100% clear silicone? Or?

3: I'm going to use tile...get it cut to size and what not..my question is should I seal the tile in or leave it loose? I feel like It would be easier to seal it in and wipe it when I clean it. Because if he poops on a crack it'd seep in between and make it a bigger hassle....so to seal or not to seal in my cage? If so what do I seal it with?

4: Should I use slate tile or another type?

Pics below!

I almost forgot some pics of Draco! First one is a comparason on my girlfriend from the first day I got him to last week and then him on my shoulder last week! He's so cute! he's on a good diet of a bunch of dubia roaches with romain lettuce/roaches/small super worms mixed in daily!

Lovely looking build so far! I prefer the sliding glass doors personally but can't see why flip up wouldn't work (might get heavy though)

1) I have used polycrylic and polyurethane - I honestly prefer the polyurethane and will need to be re-sealing the viv done with polycrylic after only about 5 months. I may not have put enough coats on though. The polyurethane cage is going on 3 years.

2) yep

3) when I used tiles I left them loose. Poop did get up under it but I'd just take out the offending tiles and clean up. Part of the reason I don't like tiles though. Nynsure what would work to seal them since I never went that route.

4) I prefer natural slate tiles. Nothing else has had enough traction for my tastes.

Draco is a little cutie! I'm sure he will love his new home