I have 2 suggestions:
1. Add more tokens to cover anything collected from a customer for the notifications, confirmations, invoices, etc. (ex: calendar name, etc)
2. The 'Limits' page does not make sense as is. For the date you choose, the min & max should be independent of each other and the min and max should NOT be based on the number of days chosen in the date field. For example, see my setup below:

Jan 1 - June 30 : min = 2 nights, max = 10
July 1 - July 4: min = 3 nights, max = 10
July 5 - Dec 31: min = 2 nights, max = 10

So basically if you book anytime before June 30th or after July 5th, the minimum night stay is 2 nights with a maximum of booking 10 nights. However, during July 1 - July 4 if you book, you have to book a minimum of 3 nights but can still book 10 nights max.

Currently, this is not possible with your script. If you book between July 1 - July 4, it only allows a max of 3 nights (= number of days in the date field). If someone books between July 1 and July 4, I want to control the minimum amount of days but I may/may not want to limit the maximum number of days. As it is, this does not work!