Buying a Multi unit property as long term investment

[muse017]

Since my father decided not to expand his business(retail) due to staff issue, he is looking to purchase multi unit properties within the city limit. He did own/built smaller units before at some point however it was on small town(<600) and he believes things are bit different in the city.

Any things to look out for?
What is the average Cap rate/or ROI in Calgary area?
What is the maximum amount you can borrow from Major banks(BMO,RBC etc...) based on property assessment or appraisal.

Thank you in advance