Those are pretty reasonable questions! Do you have a picture of your palm to upload, that would help a lot. If it's 6 feet tall you probably would want at least a 7 gallon pot (maybe 1 1/2 foot across and about 3 feet deep). You don't want too big of a pot because that will cause problems with water pooling at the bottom.

I think when the weather gets warmer if you can take it outside on some rainy days to get some rain or let it just air out in the shade, that would really be great for its health. The aren't perfect palms for indoor growing 365 days but do pretty well if they are spending the winter indoors and the summer outside.

Soil should be well draining but you don't have to go too crazy with it. Normal potting mix should be good, a little extra perlite for draining might make it a bit happier and I think gravel at the bottom of the pot is pretty important to keep water flowing out and soil from eroding with it, so I would use that too.

If you are really looking for a hard to kill indoor palm, look into the Chamaedorea species. They are just about perfect for indoor growing since they stay small and a bright room makes them perfectly happy.

Spindles are awesome palms too. Good luck!

They actually are quite easy indoors, though not so readily available. They will tolerate dry indoor air better than most species. They do quite well indoors even under artificial light. One big caution, they burn SEVERELY if you if do not acclimate them and end up moving them outside for the growing season. I love them, VERY tropical looking, but they are also soooo big! I would not be in a hurrying to transplant into too big a container without the space. Not sure about the dimensions suggested above. I am bad at assessing by "gallon size", I basically eye ball it.