don't need it as a investment just for sending and receiving but still want privacy and protection
how about mixing different options?
for example lets say you have 1
BTC and want to have 0.1
BTC ready at hand. you can keep 0.9
BTC in your cold storage (like paper wallet) and 0.1
BTC in your hot wallet (like simple Electrum desktop wallet). you can also use multi signature options where you store different keys in different locations separate from each other, that way it can offer the same security as 2FA but in a harder way while giving you bit more privacy.
depending on the level of privacy you are looking for, your options change. if you want full anonymity then you shouldn't even use bitcoin. if it is lower level of privacy you require then you should run a full node since with an SPV client you are still relying another node and you send that node all your addresses which they can link together and store and that is not possible with a full node.