My wedding is right around the corner, we leave on Jan 27th. I too haven't heard from Ana in over a month and it's definitely making me nervous. I don't have all the answers for you but here is what I can tell you.
My understanding is that a welcome dinner can be booked at the a la cartes, but there is a fee for a group larger than say eight people. Ana can book you a welcome/rehearsal dinner at the buffet for no charge. Just let her know when you'd like this.
I am bringing my own centerpieces and decor as well. I was told by other brides that Ana or her staff will put these out for you (but I have two people travelling in my group prepared to do this as back up)
I don't know about the table cloth options.
You can definitely bring your own decorateions for your cake and the resort/Ana will put these on for you.
When you arrive at the resort, Ana will send you information about when you will meet with her to finalize options. This is usually the day after you arrive.
You can hang paper lanterns on the lobby terrace, but you will need Ana to rent a large pole to attach them to (I had also asked, but I would be renting the lanterns from her or her party supplier). There may be a fee for the pole set up, but she can definitely arrange - she said she could even do this for me once I arrive at the resort if I make it as a last minute decision...
Hope that helps.