Yes you can! It is very important to be mindful that starting on a Direct To Lung (or DTL) device may be a learning curve, but let's learn!
While a lot of pod devices are MTL (Mouth To Lung) where the vapor is held in your mouth and then transferred to your lungs via a second or remaining breath, a DTL Device is directly to your lungs, think of like when you're about to blow up a balloon. The big breath you take is similar to the vapor from your vape.

It's suprisingly easy to clean a subohm tank, all you need is warm water!
Simply pull your tank apart and either dispose of or keep your coil safe away from the water, and rinse it all!
Dry it with paper towel, a tea towel or even airdry.
Put it back together and you're ready to fill your juice again!

Not at all!
You can put any tank with a 510 thread pin on basically any mod with a 510 thread! How awesome is that?