Well, not the best thing to do, but if you're the only user, you may never notice a thing. I doubt any app or process is going to do anything untoward that it didn't already have write or execute permissions to at the group or global level.
EDIT: Looked at my own. ~ is 755, ~/Library is 700.
There can be potential issues, mostly concerning security. I suggest running Disk Utility and do a Repair Permissions. That should take care of most of this, though won't undo all the changes.
There can be potential issues, mostly concerning security. I suggest running Disk Utility and do a Repair Permissions. That should take care of most of this, though won't undo all the changes.