1. con is more expensive. Pro is more colorful fish and corals. I like tinkering around with equipment.
2. Same as FW
but you have a lot more options (skimmer, sump/Fuge, powerheads). You an keep it simple HOB
filter with more water changes or more complex plumbing for sump/Fuge with live rocks and circulation pumps.
3. Same as FW
0 ammonia and nitrite with some nitrate
4. Same as FW
5. Provide minimal light and cure it before intro to tank
6. Same as FW
siphon and Algae removal