Merging Kuva Weapons - Can I swap Elements, and get increased damage- while keeping Forma?

[setcamper]

Got a Kuva Quartakk that's 26% heat, no Forma or Catalyst, but max level. Current Quartakk lich is 57% Radiation. I know if I merge the Radiation into the heat the weapon will stay heat/max level, just more damage. Would the damage be maxed or is it an average- not sure how the damages merge other than the number always goes up?

What if I wanted Radiation- and merged the old heat into it? Would the base damage be better going that way? If the Heat had been Forma-ed, does that all go away and I get an unleveled/blank Radiation gun?

Finally, any advice on Element? Seems like Corrosive was all the rage for a long time, but more current guides I read about Kuva weapons usually recommend radiation or heat.

[(PSN)Shyuu-]

Actually, if you merge the rad one into the heat one, the elemental dmg will go up and the weapon will turn into a rad one. You will keep the forma and the catalyst tho. If you do it the other way around, you lose both the forma and the catalyst, but the weapon would stay with heat damage. The wiki page should answer all of your questions: https://warframe.fandom.com/wiki/Valence_Fusion