Maybe I am not reading this correctly, but I don't hand plane on my dining table, typically.I don't think that the issue is whether it will support the weight of you or your table top but rather the side-to-side racking that can occur with lots of hand planing from end to end.
Everything is together now and am feeling no racking when i push on either side so hopefully all is well. All goes well i should be able to get it painted this weekend and the top attached.