beginner is cracking his first md5

Hi there, i am very new at this...but interessted in, how things works,
i like knowledge, so then i want to ask some questions...

It took some time, until i get it running with GUI. But the HaskillerGui shows always the wrong Path.
And i cant save any settings...dunno*

Also take some time to find a 16 digit password xD

So now i crack my first password, finally.
I have made some passwords md5 online encrypted (no salt or something) and try to crack them with hc.

PC-Desktop:
Windows 7
i7 4790
16GB DDR3 (2x8GB)
Radeon R9 390 (4GB)

My Setting is
- Brute-force
- Charset1:\combined\German.hcchr
- Charset2:?dabcdef
- Mask:\rockyou-1-60_cleaned.hcmask
- inputfile is just a TEXT with Hash inside

Status:
- 46 minutes running time
- 70384 kh/s (70.44 ms)
- Recovered nothing

Password is just
- 74147
- c613df44969c7946afc40efaacdc99d0 (MD5)
___

At first:
-1. Are my settings stupid? i think yes...because checking the candidates in hc-status, tells me,
there are too much letters, but wow* the complexity is crazy, 8 letters and highly random...
and there are also variatins like "xyxy1212"...i am am fascinated

1. How to find out wich encrypted style is used?
2. what should i set up for the above passwort and crypt-style?
2a. what should i use for "123abc"?
2b. what should i use for "abcdef"?
2c. what should i use for "$$abc"?
3. can i crack more hashes stored in on textfile, with same crypt-style?
4. do i need uncheck "CPU only" to use GPU also?

I think thats all for now.

And hopefully i find some german tutorial stuff.
if anybody know anything....tell me

Cheers.