Venues: Easily accessible with good local amenities, i.e. easy airport/motorway access, hotels/restaurants etc. Easy spectator access, the more public/local paintballers you can attract to a venue the better the trade village will be supported and the happier they will be to attend and support the series. Improved viewing with some form of field side speculating facilities for all fields, not just the CPL/SPL.
Unify the playing surface, if not over all the venues, at least at individual venues, be it real or artificial, as this effects playing style, especially where some of the fields are on grass and others on astro. Would also put a stop to the endless footwear threads prior to events.
With the above in mind, obviously the more 'showcase' the venue the more expensive it will be and therefore ultimately more expensive for the teams/players. though a minimum venue standard should be addopted and some of the recent venues have not ticked all the boxes required.
Reffing/Field Rules: Abolish team reffing, it only leads to complaints of bias and unfair advantage in ranking points, while it is a viable way of reducing overall costs to the organisers I feel this is outweighed by the bad feeling it generates.
Keep the 1-4-1 rule for minor infractions, but replace the more severe penalties with a penalty box (a la PSP) system, this makes teams work harder when they have a player in the box and introduces more tactics to the game.
There has been a relaxation of some of the more anal rules (stickers/layers etc.) and rules should concentrate on safety and fair play.
Bring back the self-check area rule, as some of the penalties for un-noticed hits have seemed particularly harsh since its demise.
Republish a comprehensive and up-to-date rule book, rather than an out of date one with appendixes.
Gun rules: Current rules are good, the adoption of PSP mode would mean an extra shot per trigger pull and that could be construed as a safety issue by insurers.
Division Locking: I can see the point of locking the CPL, even the SPL to a certain degree, however locking the lower Divs appears to be a way of increasing revenue and making game schedules easier to manage. The most ridiculous thing thrown up in D1 this year was no-show teams actually scoring event points based on their previous ranking, without a lock no-show teams would simply get zero points, all the other teams get to play their group games and everybody would be happy. Plus it would give visiting teams (e.g. Intercontinental Cup) a chance to play in a fitting division rather than sandbagging in D2 and upsetting the teams vying for a promotion/locked spot.
Roster Locking: Remove or relax the roster lock, enforcing a locked roster from the first event is killing teams and not giving them the chance to field new blood throughout the season, player ranking would be a better thing, allowing movement between teams/guesting or even a pre-determined allowance of higher ranked players on a lower div team. Should Roster locking be deemed necessary it should only be applied at the mid-season point. Team and player circumstances can change over a season, as we have seen this year.
Spot Sharing: Introduce the ability for teams to share a spot, especially in the higher Divs, this could lead to some interesting 'guest appearances' and if adopted by all the leagues would allow US teams to play on Europe, Euro teams to play in the US etc. without overreaching the individual team budgets by having to commit to all events of more than one series for a season.