I went through the same things you are 7 months ago when we transitioned from a fifth wheel to the motorhome. Let's take your questions in order:
1. You can sell or give away your 30A surge supressor, your yellow leveling blocks, xchocks and possibly your wheel chocks.
2. Your motorhome will have a transfer switch that doubles as a surge supressor, however, that's only about half the protection you need. An EMS system (like a Progressive Industries HW50C) will protect you from all of the other electrical gremlins (high & low voltage, mis-wired pedestals, etc.) and provide an additional level of surge protection.
3. Rock guard. Your coach should have mud flaps but if you want something more, you can add an UltraGuard flap (Camping World) for about $130. BTW, there is no rear bumper.
4. Handling upgrades - your dealer is actually correct on this one. Don't spend your money until you have a few thousand miles under your belt. The Safety Plus is not a normal factory option on the Ford chassis units. It was used on some of the earlier Allegro Breeze models. The new Ford chassis are actually pretty good and I think you will be surprised.
5. Getting your Equinox set up is pretty easy. You will need a baseplate, tow bar, wiring system, and a braking system. If you are going to do the work yourself, you will save about $500-1000 in labor charges. Parts alone will set you back $2000-$2500. A good source of information is the RVUpgradestore.com
6. Individual wheel weights are difficult to obtain on many CAT scales. The easiest thing to do is the axle weights Take your axle weight, add 5%, divide by 2, and get the tire inflation pressures from the manufacturers tire charts. You will be close enough. You can ask Tiffin for the individual wheel weights they got during manufacturing however, once you load up, they won't be accurate.
Before setting off you your first trip, get some driving experience. Most of the camping stuff you know. Most of the systems in the motorhome are the same as your fifth wheel with the exception of the electrical system. Driving is very different and will take real time before you are comfortable and confident. Practice you backing skills as well although backing is much easier than a fifth wheel.
Good luck and do join the Tiffinrvnetwork.com
where there are tons of Tiffin owners waiting to help you.