apply topper wax on sealant, because sealant last longer. If you do it the other way around, your complete coating will be gone as soon as the wax is gone as the sealant sit on top of the wax.

I normally leave my sealant for 1/2 day and wax for a full day to cure. To cure ok, don't leave it that long to haze/buff, you will cry LOL.

If you are using product that has online support, like duragloss and mess, you can drop them an email to ask.

no.

Personally, I won't be bothered too much with rinsing and wiping dry after claying if I plan to wet-sand the whole car cuz it's going to get wet again (while 'wet' sanding) and also the surface is going to be compounded/polished so any marks or blemishes would be removed afterwards....just personal preference. And yeah, shouldn't you polish first before wax/sealant....????
Ok. Here's the thing. Normally, liquid sealant uses some sort of solvent or another as carrier, hence their liquid form. These type of carriers have a very mild cleaning properties. Some market these sealants as 'shine and protect'. The cleaning properties would remove, in part or in whole, whatever LSP/wax/sealant that's already on the surface. Normal paste waxes however, have very much less 'cleaners' in them. Hence applying a sealant on top of something else would be a little wasteful as some (or all) of the existing LSP would be removed, if the existing LSP hasn't properly cured. So, the idea is, if you want to top up or do a 2nd layer, use something that doesn't contain (much) cleaners in them. In general, the step is sealant (liquid) then wax (paste). Or, some times, two layer of sealants, not because to get 'double' protection but just to makes sure even coverage.

And another thing, let say both the sealant and wax you're using has very minimal cleaner. Sealants are generally more durable than waxes. I don't see any point of applying the less durable one at the bottom.....

Just my 2 sen.