antennaweb.org has all the info you need to make the right choice. It also will tell you how high and what direction to point.

Hdtracks.com

No

He should release the code and increase security and privacy within the app if he doesnt have advertisers. We dont want ads anyway.

Windows defender is all you need. I keep the free version of malwarebytes on my pc just in case something seems off. It does not start up or run in the background tho.

Its usually good enough. Mobile check deppsit doesnt work. Other things are fine.

If I cant find the app I need on fdroid, i usually just use the web version.

JB Labs has good shows. My favorite is the Self Hosted show.