Hey, first I want to second following statement
graphny Before I start, screw around all you like just remember to reinstall the os or just factory reset it before you use the phone normally.
Since your questions seem to be cleared up, I will only add that none of them is issue and a warning regarding developer options. I really advice to not use it on your main device. Having dev. options enabled allows more things to happen which are not bad until they are not triggered with bad intents. On the other hand if they are it might bring significant issues. I have been tweaking this with app manager and experienced some consequences that I would prefer to avoid if I knew ahead. The least harmful was getting my device into a bootloop with only option to fix by a reset. Specially be careful around debugging tools, both usb and wireless.