Questions re: strings

I need to be sure that my understanding is correct regarding the
following (see below).  Please comment if something needs correcting?
(Thanks!)

1.  Strings are usually available in Weich, Medium and Stark.  I've
always ordered the "Medium."  What do these terms mean, and what are
the different strings appropriate for?

2.  Is it correct that the "ball-end" string is suitable for strings
with fine tuners, whereas the "loop end" is suitable to just loop into
the hole in the tailpiece, without a fine tuner?

3.  Is it not correct to say that the Dominants are the most purchased
strings, followed perhaps by the Evah Pirazzi;  and that the steel
strings are most prominently used on the so-called "student"
instruments, and also by "fiddle" players?

BTW, I bought an extra "step-up" violin for myself and had it set with
the Vision strings;  these new offerings from the same company that
makes the Dominants are available at two price points:  the Vision
(advertised for "orchestral and chamber group") and the Vision
Titaniam ("designed for soloists in mind").

I should have perhaps purchased the Titanium because the Vision were
not suitable to the instrument I bought, and were much too bright and
don't sound very good.  I'm replacing them with Pirazzi's.

Thanks in advance,
Connie