Keep weight limits as is.
No limit in min or max crew.
Anyone under 17 does not count for weight. Getting our youth on boats before they go to college is good for the sport.
Each regatta requires weigh in with scales. Once a crew member weighs in, weight is recorded in a phrf database that is accessible by yralis members and can be used for the entire season unless they want to weigh in again. Once a crew weighs in, they may not reweigh in during a regatta.
The weight total at weigh in dictates adjusted rating. This removes the issue of needing to apply for a rating change at each regatta depending on what crew you can pull together. If a boat has a deep enough crew roster and wants to adjust weight depending on forecasts, more power to them. If you are short on crew, have last minute cancellations, etc this lets you sail without requesting a rating change with the phrf committee which you can only do right now once a year.
Ratings can change on each day if crew is different on each day. No phrf adjustment outside of crew weight are allowed during a regatta. If the crew is different each day, the ratings can change during a regatta. This will take a change in regatta management. Just because it is more complicated does not mean that it shouldn't be considered. What is wrong with putting your boat on the line with a crew selected to be the most competitive on a given day? Professional teams select the playing members for a given game all of the time. That is part of running a team, why should sailing be any different?
The regatta management will need to require crew sign up sheets and weigh in times each day. If a boat has a crew change from day one, they must notify race management and weigh new crew. Each morning a time must be established to weigh in. Phrf will need to manage the weight database by person; this not difficult to do using a simple form on site that requires a password given to race management.
This process of administering correctly allows for flexibility, fair racing, less cheating (unknowingly or otherwise) and allows the boat owner to decide how they really want to run their program. The top teams will show up with crew changes which would be allowed and what is wrong with that? Other teams will keep the same crew and be happy to be on the water and not deal with weight changes. Scoring programs would need to allow for different ratings of the same boat in the same regatta - this is probably the most did duly part of this route.