Are there pens that work like Lamy Al-Star EMR pen, with a button to switch tools, etc, on the RMPP? I have been using my RM2 for years. Backlight would be nice, but not sure it's worth the trade off for me.

AFAIK this does not exist yet for the RMPP. It would be a nice addition and I would guess that they release something eventually.

If you are generally happy with the RM2 then the form factor is probably the only reason to upgrade or swap that ends up being worth it. Most Best Buys carry Remarkables and offer an opportunity to feel it before deciding.