1) I can't imagine this being an issue, I personally would just go for it.
2) I did have EXT revalve and respring my E-Storia because it was too soft overall. I'm ~160lb rider and they originally sent me 325/350lb spring, had them switch it out for 375lb/400lb spring. Stiffened up Mid-Speed Compression without touching High-Speed too much, and stiffened up High Speed Rebound without touching Mid Speed too much.
Have a storia v2 on my Geometron G16. It does have a different feel but both feel great with a slight edge to e-storia. Hard to say how much is the bike (especially weight) and how much is the shock.
Have only had 2 rides on the new stiffer setup so still dialing it in and balancing it with the front but so far it's fantastic. Even in the tune they originally sent, it was a big improvement on X2 for me. Definitely giving me confidence to lay down some fast times on some
trails you might be familiar with.