A question for my CPA/Tax professional, I understand however I honestly don't have one set up yet so this is just for general understanding purposes at this point. 

Usually the agent on vacation has a colleague cover their business while they are gone and share some commission with them on the deal.If the agent is a long time professional the business doesn't just stop while on vacation you have others cover while gone etc. 

We have a large 4 bedroom that is currently rented out to 3 recent grads/ young professionals.

I am not a real estate professional.

I am not a real estate professional.

Understand that many professionals use this app, so there is a lot of competition so what will make you stand out from everyone else is education and persistence.Make your day productive with tools that are actually working and not drive around polluting the world.Good investing...

I do some private lending and I use Money Lender Professional software, but its like $300 to purchase the software. 

As the tenants move out, you find a really good project manager or someone that can help you with light rehab some paint and carpet work while you use professionals for the heavy stuff like changing a water heater. 

If housing is unable to do anything, hire an attorney and get them out as soon as possible, period.As @Thomas S. pointed out, you should consider selling this home or giving it to a professional property manager that can get things back on track and put money in your pocket.

Which renovations do you leave for professionals?