Used to accompany a piece of advice:I would go to see him if I were you...
For the rest, I could offer cautionary advice for a rental, but I'd just pass if I were you.
I wouldn't worry too much about that if I were you.
I'm not well versed in topics such as this, and everything I've said may be based on erroneous assumptions, so I wouldn't give it too much credit if I were you.