Bukkit

Could I use the chestcommands plugin on the PaintBall Pure War plugin I mean like from the pb lobby be able to shop without using the console just typing /paintball and shopping from the chest commands GUI. And another thing is that can I use BOSEconomy to manage the money of the plugin and use the same money on all the server? , could these two things be possible ?

There already is a shop gui once you are in a match (you can open it by clicking the book in your inventory). Later paintball might have different shops depending on the match, so allowing shopping already in the lobby is no option.

The currency was chosen to be separate so that it isn't mixed with the currency of your normal survival part of the server. The idea is that players are only able to get access to the gadgets and weapons of paintball through playing paintball, similar to counter strike or killstreaks in call of duty.
If players can now also gain this cash by other means this could either make the paintball game very boring, if players got lots of cash (or the gadgets are very cheap) so that they can buy lots of those weapons without restrictions. Or the players are no longer spending the cash earned in paintball for those gadgets, because they prefer investing it in the survival part of the server (if the gadgets are to expensive). To find the right balance here is really hard/not possible in my eyes, especially because of all the additional possibilities to gain and spend money of the server-economy.

The only situation this would make sense would be if your server is no normal survival server but a mixture of different minigames and the money can only be gained and spent through those minigames. Just like tokens on a funfair which can be spent on the different rides.

However I decided in the past to not support this kind of cash usage, because most of those servers also sell their server-economy/those 'tokens' to their players for real money, which would violate the usage conditions of this plugin ('no commercial usage').

Maybe I will add this in some future version nevertheless as option (for those servers no selling their server currency to their players). However this has not a very high priority for me among the things I want/have to do first.

Also possible is that I might remove or replace the paintball cash completely, because currently there can be very unfair situations as well, if players hoard their cash. So maybe in the future players might only be able to spend as much cash as they actually earn in the current match (or the last match, or similar).