Could park those on the open ground, but no climate control...also a big thing for people with extra $$$ to spend storing forever.Know thy customer!

As you probably know already, they have to pass Act 34/114/151 clearances, usually annually.

I don't think it would be easy to add on an extra "expense" like that and expect your tenants to pay it.

This number is going to be different across every market, asset type, and lender, but it's something that each lender should provide in their initial preliminary quote, and in most cases is negotiable.I'll usually ballpark reserves at ~$250/unit for stabilized multifamily. 

Usually they offer a "haves / wants" time during the meeting.

But maybe you get an extra 5-10k on the HELOC which allows you to get in on another deal.

I even paid for the extra HVAC coverage. 

I found a potential property and I think that's where the "extra" square footage is coming into play (the house has 2 bedrooms and 1,100 SF).I'm assuming adding a bedroom here may be more complicated because of matching the siding on the house - probably not worth the cost but I'm not sure.Anyone have experience with something like this?

Or extra information like pay stubs, driver's license, etc.? 

Not impossible to work around or deal with, but will require some extra due diligence and awareness of what you are getting into.