I like vim's tabs as a way of grouping kinds of buffers into a few categories, eg each tab might gave several split buffers representing a Django app per tab. This isn't how tabs work in most editors though.
Is there a way to expose only certain buffers in certain tabs? My experience has been that all tabs show all loaded buffers...
For this reason, I've pretty much forgone tabs in favor of minibufexpl.vim (https://github.com/fholgado/minibufexpl.vim), which gives me a pretty robust buffer-display window on the top of the editor and easy navigation keybindings ([shift+]ctrl+tab).
Nope, but I have enough space to use several splits within a tab (which is also why I stick to 80 columns for most of my code) so it's not a huge issue.
You should take a look at FuzzyFinder as an alternative to minibufexpl: http://www.vim.org/scripts/script.php?script_id=1984 I mapped <leader>b to fuzzy search my open buffers. Much quicker and less cognitive overhead for me than managing a list of buffers manually and scanning it visually for what I need.
Hmmm, very cool. I generally open multiple instances of MacVim for multiple projects. Apparently tabs can have a working directory each. Really interesting... going to have to experiment with this.