Despite having the post thanks button on my site, I'm forever deleting "+1" posts from users. It'd be great if there was a way to click a post that contains a +1 and have the forum both delete the post and add a like from that user to the liked post.
Maybe you can just do a replacement variable for posts with just "+1" in them... replace "+1" with "[I like this post, but I'd rather perform 3 keystrokes to say I like it rather than just click the handy little 'Like' button]"
I meant manually as an admin option, if you see the +1 you could use the inline mod to convert it, and part of the process would be to specify the post they like. This way it would work for
+... oh, wait.
Not the best idea to be honest, as it is impossible to capture user's intent (though, most of the time, it will be what we want). It might be best to keep something like this as an add-on, where the admin can choose to add it into their forums at their own discretion.