Open Text File From Finder In Vim
Create an Applet. The script below should get you started. Save that Applet to place of your preference (/Applications/). Select any text file and press ⌘+I(nfo) > Open With: > Other > Select you Applet, then click change all. Now whenever you open any text file that applet will run, which will open the file in vim.

on open theFiles
    tell application "Terminal"
        activate
        -- If there are no open windows, open one.
        if (count of windows) is less than 1 then
            do script ""
        end if
        set theTab to selected tab in first window
        set filePath to POSIX path of item 1 of theFiles
        do script "/usr/bin/vim " &amp; quoted form of filePath in theTab
    end tell
    return
end open

on run
    --  Handle the case where the script is launched without any dropped files
    open (choose file with multiple selections allowed)
    return
end run