In fact, I lost a deal last year because it took me too long to modify hundreds of lines of pricing every time there was a Change Order, whether from my hard money investor or my contractor. 

Some of those downtown buildings are more difficult to modify than you think.

I'll definitely be modifying my process.

I just modified an already amazing spreadsheet that calculates risk, spreads, ROI, how much debt financing/equity partners to hold in any given deal, etc.

I've modified slightly to include:An early wake-up callShower/Pray/Meditate on events of the dayRead/Pack LunchCommute/Listen to something that motivates meGenerally first one into the office.

After each one, be sure to take the time to reflect on lessons learned and to modify your business process and model as needed. 

Must we use the 8 page California Residential Purchase Agreement to put the house under contract or can we use a shorter, modified purchase agreement?

If yours didn't, modify the script to fit your scenario, "If you want we can provide washers and dryers as a convenience, we would just expect you to to fix anything if they break....

(I know it's kind of a general question but try and give examples of your own experience, it will help me modify it to my situation). 

So far only one tenet had to modify their rent, then I let them out of her lease.