1) Introducing "professionalism" - It depends on how you are defining "professional", nwb001. There is some truth to what PSMKay says, especially if you are equating "professional" to having a larger budget. Most organizations (not only the arts ones) have a particular culture and before you are employed, it is important for you to get a sense of whether that culture is one that you will enjoy.
In terms of creating change, it is very possible if there is a willingness of others. Most organizational change requires you to socialize an idea and get buy-in from your participants. That's why it's harder to change big companies - there are more people who need to buy in. If you are defining professional as higher quality for the same pay, you need to get people to share a common vision of what that looks like - and that leadership usually comes from the top, or from someone who is very influential (and either is committed to staying or has already been there for a while). It is almost impossible to create change as a new person to the organization. You need to earn their trust and understand the politics of any organization you join.
That's not to say you can't create small change that can have ripple effects - but just take it a step at a time with the things you can control. If you do want to create change, I would start with some small but meaningful things that express your standards - perhaps making sure that everyone is there on-time for every rehearsal or simply making your own behavior more professional to lead by example. If you're hoping that they'll hire different staff or designers though, that sort of change takes years of commitment. In any case, complete revolution may be unlikely.
2) the struggle and crusade - it's up to you to determine if it's worth it to you. This whole business is a struggle (which is something I've been thinking a lot about). to me, changing an organization is not worth a crusade. training new behavior is worth it. for my particular situation, this lifestyle is worth it right now (but it may not be in a few years). this is one of the few professions where your own values are routinely challenged (every time you choose to take a new job).
3) contract negotiation - as *anyone* who is negotiating on their own behalf (i.e., anyone who does not have an agent and is not part of a union), you have the right to ask for anything you want. it doesn't mean you'll get it, but you can always ask. there may already be some precedent, but if you never ask, you'll never get it and at least it opens up a conversation that might suit your needs. (recognize also that being paid for the actual time you spend working is unusual in the theater, *especially* community theater).