On the rentals section, I tried to add a new cost. The text field is limited to 15 characters. Can you increase this?

My intention was to create a new cost called Linen Change (Free) as clean linens without charge one time per week for clients that stay more than 1 week. I wanted to add a cost of 0 since this is complimentary. The system wouldn´t accept a cost of 0. It says it must be more than 0. Can you please remove this limitation, or let me know how else we can be alerted and track the dates and properties that we need to change linens? I thought the cost field would work well because there is a date due field attached to it and we want this information to show up in our cleaning schedule.

Finally, somewhere in the booking details area, we need a field that states number of people staying in the property (so we know how many sets of towels to provide) and any special requirements such as cot, high chair, and how we have arranged for them to collect the key. How do you suggest we add this information to the system. It needs to appear on our cleaning schedule.