They can properly secure the house following the tenants' departure, winterize it, coordinate utility account transfers, and source vendors to address anything that needs to be done to the house prior to marketing it for another tenant.

I think the vendors have some of their in house rules.I'd check with different mortgage brokers to check this.I've also heard getting the 10% down 2nd home loans are currently harder to get.

I actually learned a ton from them about analyzing properties, investing, self-managing, seller financing, vendor connections, avoiding common mistakes, etc.

My PM uses licensed/insured completely seperate vendors for repairs so it’s easy to call those companies as an individual and see you are paying less through them because of their volume.

So, if you aren't producing then you are costing them money being on their books normally.As mentioned, plenty of agents, and other vendors, on BP are pretty bad, too... 

*This question is for any property manager or people with prior property management experience*What would you say are the biggest issues that reoccur when dealing with tenants, vendors, etc?

As long as you're making a good faith effort toward getting vendors out, getting estimates and keeping the tenant updated they just have to wait on your process. 

They will do the price shopping for you and find the based vendor based on your requirements. 

And a special thanks to @Sheryl Griffin for shedding a bit of light on this vendor.

You will need to supply 2-3 quotes from different General Contractor's or licensed builder for all work.Some things that can occur are builder/vendor issues with lack of inventory, broken material, employee "no shows", date of completed work extensions, bad work, additional costs not factored on blue prints or cost analysis, delayed permits.Keep in mind any delays or issues will slow down your clear to close/funding date.