Rather than spend a few hours before abandoning, do you think and advanced vim user could successfully make the jump?
Of the features you list, you can record macros into a buffer (qa...q, @a works) but you can't "ap to edit them. Text object support is pretty solid. I don't use pathname completion in vim so no idea, switching panes is reasonable (at least on OS X) but you can rebind to something more vim-like without too much trouble.
It's taken me about 9 months to migrate, the big holdup for was correct text objects (any multiline object was linewise for a while...) and ctrl-i/ctrl-o support. For the latter, I found a plugin that mostly did what I wanted and patched Vintage in about a half hour. Vim compatibility has improved greatly since guillermoo and msfio started hacking on the Vintage repo.
As for whether to switch, the advatage of ST is better plugin API, which matters to me since I do write my own plugins and first-class support for a lot of the things I had as plugins in Vim (snippets, project drawer, autoclose/surround, project fuzzy search). I keep meaning to do a vim-incompatible Vintage "s for select" plugin which would do text objectish multicursor selection but other projects have been more pressing.