[Dearth]

As Kien said everything in this hobby is about your personal preference there is no one answer for this hobby which can suck

Bare bottom vs sand is all in the eye of the beholder some people love the bare bottom look and maintain bare bottoms are easier to care for. Sand or crushed coral bottoms add their own particular flair and beauty to a tank and sand is a requirement for certain species of fish and inverts.

As to lights both are good but if you are familiar with Radions stay with them why mess with something that works

As to aquascaping again its personal preference but some features that are somewhat nessecary are hidey holes for your fish the more hiding spots available the more likely your fish will stay in the open where they can be seen rather than guarding their hiding spot if limiting their hiding spots.

Caves or over hangs are also a nice feature and fish are attracted to them like moths to a flame

Experiment and feel free to ask questions never be afraid to ask as its the worst thing you can do in this hobby is not ask even if you think its stupid