Does the SDS swerve Mk4 need some protection on the gears?

Definitely. It’s very important to grease your gears with white lithium grease. If you are talking about a cover, it’s very nice to have a 3D printed cover to protect your gearbox. There are many open source models for MK4/MK4i covers online.

Do you (or anyone else) know if there is a difference in Red-n-Tacky and Red-n-Tacky 2?

Pretty sure it’s just packaging. The 1st one is sprayable and the 2nd one comes in a can.