I won't try answering everything but have some suggestions...

On the RealTracks page, there are demos of all of them. Browse through and listen to some. That may help.

You don't need any RealTracks to use BIAB. You can selectively download and try them out. The download links have a expiration of about 3 days though. There will be a learning curve to overcome. There are a lot of features and the interface can be overwhelming. The tutorials and forum are very helpful.

And remember, there is a 30 day trial.

R