"1st - What is a "faucet" and for what does it serves?"
My limited understanding is mostly used to advertise other services, gambling, games ads ect, free coins being the hook.
Not something I would look into.
"2nd - What's the diference between mining on a stratum or getwork protocol pool, and a P2Pool? What is the more profitable? My hashrate for bitcoins is 180GH/s and for altcoins is 2.7Mh/s"
Getwork is obsolete, do not use it. At All. Old and used by Bots to spam networks now.
The reason this pool is here is to help you gain knowlege of how this works, If your miner is supported I would recomend this BitMiner client to get started.
I am looking forward to getting to 1gh, You are starting at 30 ? good for you, stay away from altcoins at that speed Bitcoins will pay if you are patient.
If you must collect Alt coins (in case they skyrocket) 5 each held, would at least make you not kick your yourself
Later on when they go up
BitCoin @ 10 bucks a coin is long gone, and I missed all that.
"3rd - Are there any advantages on solo mining vs pool or p2pool mining?"
Dunno, but you need alot 350+ gh to even try solo, prolly more.