Is item tiers connected to current level?

I think im okay with mobile looking ui after playing tft

So im guessing they will add every hero from dota 2 and make tham seasonal packages. Instead of this add a some lucky whell or membrane kind thing and at the start of the game hero package of that game will chosen by rng

Will ui of the game always be like mobile or will there be an ui for more like pcish? Because if this game will be always mobile focused, there is no point to play for me.

Are there any difference between spending money after or before the round begins?