How would you handle these repair requests?

[Joe Edwards-Hoff]

So, I rent out my basement floors to some friends. We have no lease and it was intended to be short term.  The term has gotten longer, which we're ok with, but now they have some "needed maintenance". 

1) I have yet to see it, but they told me that there is black mold on and around the bathroom sink. His solution is for me to entirely replace the sink AND the cabinets that it sits on. My initial thought is to clean with a mold killing chemical and then watch it. Agree?

2) they've had me already go down once to fix slow draining sinks. My thought is that at this point they need to take care of it.  It drained fine before they moved in. My assumption is that sinks don't clog themselves and that it is a tenant responsibility.  

3) aside from that there are a couple cosmetic things that never got completed before they moved in. Like a section of crown molding getting painted and a floor strip between two rooms being installed. I figure if it is a big deal I can do that. 

What do you guys say? More than anything,  I wanted to get a second opinion so that I could confidently tell my friend that I did it. That way I researcheddar my decision.  

Thanks