[SOLVED] Where do i put my graphics card on a h81m - s2pv and some other questions

1. Yes that is correct, this card needs no Power Input from the PSU. The power from the PCI Express 16x alone is enough.

2. You should put it in the first and ONLY PCI Express 16x slot of your motherboard.

3. No, it will not interfere with the audio, it should be perfectly fine. Should there be any issues, either you A) did something wrong, or B) your motherboard or gfx card is faulty.

4. No, you cannot put it in the 2nd slot, as that is an old PCI slot and should only be used for old cards like network cards, sound cards etc that require a PCI slot.
PCI and PCI Express are not cross-compatible. You cannot put a PCIe (PCI Express) card in a PCI slot, and vice versa. It simply will not fit, so its even foolproof. Should you somehow manage to stick the graphics card in the 2nd (PCI) slot, then it will either damage the card, the motherboard, or both.

5. As for the RAM, its always good practice to use identical ram sticks so they are not only compatible, but they also will operate at the proper timings, frequency, etc. However, if you have no other choice, then why not try it and see what happens.
DO keep in mind that the Ram sticks need to be DDR3, so they can fit into the DIMM slots of your motherboard.
EDIT: Looking at the specification sheets from Kingston, it seems that one of those 2 (kvr16ln11_4) is a DDR3L, with lower voltage (1.35V), and even though it can function at 1.50V, and its timings and frequency are identical to other one, its got 2 Ranks of 8 modules each vs the 1 Rank of 8 Modules of the other Ram stick.
Specifically,
KVR16N11_4 - based on sixteen 256M x 8-bit FBGA componenents
vs
kvr16ln11_4 - based on eight 512M x 8-bit FBGA components

This isnt a particularly great sign for compatibility, but again, you can just try and see.
The most important thing is, the voltage. Your motherboard SHOULD detect that one of those 2 requires 1.50V to work, and should set the voltage accordingly. And of course, they will both function at 1.50V.
Now, as for the Dual Channel, it may or may not be able to be enabled.
Chances are, they might work in Single Channel mode.
Again, you can just try and see.

I would guess that they will probably be able to function properly with no issues, but guessing isnt exactly my thing. This is the kind of thing that you need to test, to see if it works.

As for me, I'd probably just get 1 Ram kit, that features 2 identical Ram sticks, and be sure. No hassle, no issues, and I can rest easy.

Sources used:
https://www.kingston.com/dataSheets/KVR16N11_4.pdf
https://www.kingston.com/datasheets/kvr16ln11_4.pdf
http://www.gigabyte.us/Motherboard/GA-H81M-S2PV-rev-30#sp

- For best results, someone with experience/expertise should install all these modules in your PC. By doing this yourself (since you said you are inexperienced), you acknowledge that there's a chance that "things might go wrong", so be prepared for that. Always read the manuals of every product, consult with the manufacturer's webpage, and try to figure everything out beforehand.
Posting on Tom's for help is a good idea, however you should know that you're basically asking for people's opinions, and they (including me) can be wrong.
In short, all responsibility lies with you, I hold no responsibility for any damage to your items or goods.