Hey, how are ya?
Dwarf Lion fish are venomous, which I am sure you know by now, but they are also detivores that can quicklt pollute and degrade your water quality in a short period of time.
Yes, it is possible to maintain a marine and even reef aquarium without a skimmer! I know first hand of this scenario as I have a 35hex with nothing more than a carbon supplementation.
Though it is not a good habit to get into, especially if you get involved in certain species of corals and Tridacna clams, it can be done. I would think about investing in a skimmer as it will be more beneficial than just using a biowheel, in my opinion.
I would also refrain from going with a Dwarf Lion if I were you, as serious consequences can arise, especially if one is not careful or is too comfortable in his/her ways! Plus it is kind of a small tank for the Lion.
You do not need specieal lighting for live rock as PC's, T5's and halides are acceptable lighting arrangements.
As for the amount of live rock, I would try for the more porous of live rock for optimal benefits and reduced costs(porous= like a sponge, light and many holes, nooks and crannies).
Enough live rock to fill about a quarter of your tank is sufficient and I would refrain from making it into a wall and building the rock up against the back of your glass tank. This reduces the amount of water flow to that part of your tank. _________ 125gal.w/Mag9.5 return(dual megaflow)>Mag7 pump Aqua Cev180skimmer.Wave2k Hamilton Reefstar(2)250watthqi(mh)pend.a Yellow, Naso Tang Red Lip Blenny Percula Clown Demoiselles Niger Trigger F. Wrasses Ceriantharia Orn.Shrimp and Stars Hermits Queen Conch asst. snails> Stars Zoos shrooms Montipora Brains Gorgonians Favia Turbinaria(large+small polyp) Acropora Xenia Tridacna (CroceaMaximaSquamosa) Leathers <35+75gal.reef tank as well> 
"IF THE PHONE DOESN'T RING...IT'S ME"  jb  | 
