Here's my opinion regarding your questions.
1) Can anyone confirm that the Ride EX and K2 Indy chassis dimensions are the same as that of the Ride RX & Delta MVMNT, and K2 Formula, respectively?
The chassis within brands are usually very similar in sizing, so they should fit the same between models.
2) If there is no space between the binding sides and the boot, will these create pressure points serious enough to notice?
The answer should be no unless you are cramming your boots into the binding or the boots were hurting your feet to begin with. You don't want too much space between your binding sides and the boots.
3) My boot fit into the bindings, but I was only able to ratchet the toe strap down three notches on the toe ladder max. Will this be an issue?
It shouldn't be an issue. I have the same problem with my Targas. The only issue is that it's a bit of a PITA to get the ladder locked in sometimes. If possible, you should see if you can get longer ladders. It'll make your life easier.