some basic questions related with "SoundFonts" Handling

Hello friends,
I am a native german speaker, therefore please forgive me some language mistakes.
I am a kind of new to the "world of Midi and SoundFonts".
I tried to get information from the musescore manual but also from wikipedia and the internet.
There are still some questions left, and I do hope, to get the answers here.

To my understanding, MIDI prepares "places" or "Channels" to be filled with "sound".

Q1: How many "places" is prepared from Midi for one "SoundFonts-Set" maximum?

The soundfonts do fill those "prepared places" .
Therefore there a LOT of possibilities to fill those places - just depeneding on the content of the SoundFont.

But my problem is, that using a Soundfonts is very timeconsuming - to find out, which sound is included.
So far, I am testing it, in loading it into MuseScore, than choose an instrument and listen to it.
But often - not every channel oder Midi-Place is filled with sound.
The result is "no sound".
Therefore here is my next question:
Q2: Is there a easy, - freeware - program - just to test the soundfonts.
Which shows me in one moment, which "Channel" of the soundfont is really filled with sound,
and also to listen to the sound with "one click" on a "screen-keyboard".(since the sounds are different in
different pitches)

Q3: The next step would be to have something like a small program, which I would call "SoundFonts-Manager".
Until now, in musescore, I have to decide for a special "SoundFont-Set".
But often, if for example, the Sounds of Brass are very good, another SoundFont-Set has much better Drums
and percussion sound.
Wouldnt it be good, to be able to make and arranged my own special "SoundFonts-Set" - using the best sounds
from different SoundFonts-Sets, and adapt them exactly to my own needs of a special piece of music.

This might sound complicated, but I have the feeling, that there has to be a lot of programs around doing exaclty this.
Does anybody know more about this issue?

Q4: This is probably a very simple basic question.

Are the NAMES of instruments and groupnames given by MIDI and cannot be changed (the names,- not the content)
or could also the Names of the instruments be changed by the SoundFont-Maker?

Q5.Is there a rule or convention, how the names of the instruments in MIDI are filled with sounds.
For example: If a SoundfontMaker wants to make only Drums and Percussion.
Could he also use the "Brass-Group" and fill them with special Drums-Sound?
Or a Sounfont-Maker, specialized in Organ-Sound. Could he fill even Strings or Percussion with the
sound of Organs?

OK - so far. Those are my questions. I would be very happy and thankful,
if someone finds time to give me answers or some hints - where to find the answers.
Thanks a lot for your efforts.

Sincerly yours

Steve