Can it really outweigh the benefits?

@Holden Davenport - I agree with @Brian Garlington that the benefits outweigh the cons. 

When you pay off the account and it is now considered “closed.”1 and 3 are petty impacts and do not outweigh the benefit of what you took it out for.

I am considering becoming a licensed agent myself - I feel the benefits to an investor of pursuing a license outweigh the costs and/or lack of experience of an excellent professional real estate agent.

That way when that glorious day comes in my REI career that my passive outweighs my W-2, when I'm walking out that door flipping double tall man's, I'll have a hefty chunk of self directed funds to invest with

The pros outweigh the cons for me (most days), but it's always a struggle.

At what point does cash flow outweigh appreciation, if ever?

If you take on your friend as another tenant, it may help outweigh some of the potential cons that would come along with this process.Hopefully an expert in this area will be able to provide a more concrete response, but I unfortunately don't believe it will work out as you have proposed.

Does the income, steady job, and long rental history out weigh the bad credit?

The potential protection from an LLC far outweighs the downside of using one (fees, slightly nuanced tax returns).You might also look into an umbrella insurance policy in case the LLC shell is pierced in a lawsuit.