WELCOME TO AA!!!
Please do not cycle your tank with live animals.
I have a fluvial 304 on my 55, but I don't run a skimmer
1. You should shoot for 1.5-2 Lbs of rock per gallon. You can save costs by mixing base (dead rock) with either cured or uncured rock. ASM is a good name brand for skimmers, since I don't use one, I think you might want that size or double the size, I can't remember, we'll need some one else to chime on in that one.
2. Answered in one above.
3. You will want more rock, that and the substrate is where most of your beneficial bacteria will reside, not so much in the filter (but it will still host some).
4. A sump is another "tank", folks like to use this to place items that clutter up inside a tank, like heaters. It can also be used to place macro algaes for nutrient export. One big advantage is more water volume, which leaves more room for error.
5. That is a great idea, I have 150 LBS of base in my 125 and seeded it with LR
. It should take 4-6 weeks to become live (as in hosting the beneficial bacteria), depending on how much cured LR
you use or seeded sand (sand or rock from an already established tank).
Don't be afraid to ask questions, we were all new to this at one point and asking the same questions....