We are deciding between hiring a property management company, finding a full time handyman or a hybrid of hiring a property management company for our bigger buildings and using a handyman contracting company for the easier ones.

I'd recommend communicating more with the PM directly.

Some of these bookings we get through marketing partners who build these relationships and charge referrals fees for finding the housing.

Do not communicate with the tenants except as advised by the attorney.

Is communication prompt and reliable, K1 delivered on-time?

We communicate almost everyday.

Assuming you already paid for the first occurrence, if it happens again and the plumber doesn't find anything wrong then, yes, the tenant should be responsible for the invoice.Your PM should be setting those expectations when they communicate with your tenant."

I would work on my communication of my processes including letting them know asap of their schedule with me. 

On the other side, the bigger companies have more experience and their numbers tend to be more accurate (not always)... as they are big companies "their costumer service" and communication is better but at the same time they "have more mouths to feed" if we need to be honest so can get a bunch of ok or good deals but I kinda doubt they will be great (just my personal candid opinion).

Here's how I see the strengths of Podio:- it does CRM, Project Management, collaboration, and communications--all in the same system.