Weapon changing with one button press?
No.
You can have only two active weapon set.
You have to open gear window to change an active weapon set.
Nope. There isn’t. Would be nice to get that feature from GW1 where you could have up to 4 sets prepared. One set in hand, the other 3 were in the pack. It would be a nice QoL change to have the primary and secondary set equipped with the option of having a 3rd or even a 4th set in the inventory.
To add on to that, having the option to insta switch, while out of combat of course, into a different set up. For instance, my necro has a condition set, a wvw set and a zerk set all using different traits. It would be a really nice QoL change to have a panel where you can create and store equipment + trait profiles which you can load while out of combat.
I don’t use the equipment panel too often outside of checking my uses of gathering equipment and using upgrade items (Runes, Sigils, etc.)
Instead, I put my weapons in my first slot bag, and when I want to switch weapons I open the Inventory and double click in there. I haven’t yet, but you may want to make the first bag an Equipment Box so that fewer looted items automatically sort to it unintentionally.