I'm not necessarily planning on staying in the short term rental game long term, but our market is under-saturated with STR and since I bought the house with cash, now would be a great time to experiment with how I like STR and if I want to consider doing some STR's with some future BRRRR properties.  

Title says it all... this is in my personal residence but I’ve found BP to be a more credible source for answers than searching the web.After 2 or 3 showers the water gets cool/lukewarm, not freezing and will stay that way, can usually get away with a shower in the morning and one at night without problems but if it’s the kids in the tub and a shower that pretty much uses it up.Typical usage, nothing too long, any help?

I would stay away from the pebble rocks, based on looks. 

You didn't say whether they stayed or not.

Just a few things I did to help me save (and they added up):- Cut out the cable and use wifi/Netflix - Make coffee at home - Stop eating out, only making it a special occasion here and there- Stop buying unnecessary clothes - Switched from a 35$ a month gym to a $10 a month gym- Cut out "snacks" when grocery shopping- Quit smoking cigarettes - Be mindful of utilities, shut off lights at night, don't leave them on- And most importantly, stay busy.

I’m reading a book on the Great Depression right now that talks about the importance of staying liquid so you can pick up deals in stocks and real estate.

Stay in close contact with them.

In our case, the tenant stayed, and we haven’t had any more drama on the street.  

Again, we reach a verbal agreement and again, like deja vu, one of the tenants messages me the next day (9/10) and says she will not be signing the new lease and will leave when the current lease is up.Now, only 2 tenants are willing to stay and they're arguing that I'm not giving them enough time if they need to move out by 9/30.

She always stated that in two days she is going to move out, but keep staying in my property.