It should have an inverter/converter, as almost all newer Class A rigs do. If not, wiring "should" be in place to have one installed.
As for the Flexsteel chairs, you may want to check out new chairs at a RV furniture business in Long Beach, California. They may be cheaper than having your existing chairs recovered. The new chairs should bolt right in on your existing brackets.
The macerator is for grinding up waste and pumping it to a dump site that may be uphill or some distance from your RV. It also makes it easier for a septic system to begin the conversion process. Otherwise, a macerator isn't really needed. I had one on my boat (to pump up to a sewer system while at the dock), but I've never had one on my coaches and never needed one. So, it is up to you to use it or not.