If the building has a heritage designation, or you simply wish to preserve the elaborate external trim or dentil or internal mouldings, these things are time consuming and skill sets to restore them, uncommon. 

For larger projects, a 10% down payment and a draw schedule is not uncommon where I am, just to show commitment and ability to pay on the clients part; but 50% would be a huge red flag that he’s either flat broke or looking to scam you.

It's too small for the commercial guys to "waste their time" on and it's non uncommon for residential Realtors to list those properties... and completely mis price it. 

Returns in the 10% CoC and 20% IRR (although getting more challenging is not uncommon in value add deals - 5 yr holds are common).9) Yes, nice to see the GP invest but honestly, the GP is risking a ton in these deals..call it sweat equity, putting their own net worth at risk even if non-recourse, situations could occur drawing back bad boy clauses that risk the GP's personal finances.  

Paul, I am referring to a 5 year balloon...and/or interest only periods that are much longer than 5 years with much longer fixed rate periods (upwards to 30 years fixed).  3 years I/O on a 10 year loan is not uncommon...sounds like you are at 5 years I/O on a 10 year on one deal.  75% leverage can be problematic with many cyclical and hybrid markets or under capitalized properties...and not problematic with other stable markets and properties.

@Gregory Ballard, it's uncommon (Usually I will see 5, 7 10 year terms), but it is possible to get a 30 year fixed rate from Fannie.

I think it also depends on the type of purchase as well, highrises it is extremely uncommon due to the height or floor level of the property. but it is at the buyer's discretion if that is some additional inspecting they want to do. 

One of the trustees use to live there 15 years ago and remembered water coming in.This property is in Wisconsin and old foundations with cracks are not uncommon but I have no experience with block foundations.If I write on the offer I plan to have a contingency to get the foundation checked out to make sure there are no issues. 

A guaranteed period of interest is not uncommon. 

Not uncommon to go threw a few until you get the right one.