There are no other limitations on encumbrance. Your backpack will hold as much as your strength can. Yes, there will be banks and storage. The fun part is, you build your own bank and item warehouse in colonization. This is your own bank, your own warehouse.
Nations also get storage in their warehouses as well as a separate bank just for use by the guild.
Yes, we plan on having multiple servers, and the current estimate is about 1500 simultaneous users at peak. We're real big on not overcrowding our servers. Traveling between zones will be nearly seamless - a one second pause, and then you're running normal. We have some interesting things planned for a unique approach to servers Something I can't get into just yet. Currently, one can have up to three characters per server.