Okay i am running SPV, atleast i think

.
If you chose SPV (over Native) then you are running SPV

.
So if i understand well i can park my coins in the wallet and close everything and even then i receive some interest.
Yes you can close the wallet. Your address will accrue
interest, but you have to claim it manually (you have a button for that) so that it's added to the balance of your address. If you want more
interest, you should claim frequently.
Okay cool, by claiming frequently it's possible to compounding the coins which is cool of course.