If you actually have a budget for your project, consider making a clear distinction between who is paid a predetermined amount, and who is volunteering without expectation of payment; as far as donations, you could have some documented policy about how donated funds get split between the volunteers based on their roles, and then publicly disclose your donations.

In your reply to @SimpleStacker you also mentioned "in my country"; if your project is significantly tied to a local economy, then the reasonable compensation probably depends on the activity of that local market, even if some of your volunteers are remote workers from somewhere else.

Once, before Bitcoin, I did a lot of volunteering for a charity project where I lived. I really enjoyed the time I spent doing it, and it was a pretty vibrant little project. It got to where I was spending so much time doing it, they offered me a little part time job. I was young and I probably should have said no. But instead, I accepted. That ended up making it less good. They weren't paying enough for anyone to sustain themselves on the income, and now I was feeling like we were in a employment relationship -- which meant I expected to be compensated fairly. I wish I had just remained a volunteer and made it fit in with some other kind of paying work.

All this to say: it is perhaps better to pay people what the job is worth or not at all. Charity rates can lead to people feeling grumpy. Now, perhaps you could arrange to distribute a thank you gift of sats every year around the holidays or something. Still reward people a little, but make it feel more like a really heartfelt thank you.

It's a little unclear from your post whether you plan on advertising these roles or you already have them filled. If you plan on advertising them, you could advertise them with the rates you think are fair, but I suspect if they are far below market, you won't find the people you want. It may be better just to ask for volunteers to do the work.

If they are volunteering they probably don't expect to be paid for their efforts. I think you should wait until you can gauge each individuals level of contribution before offering any sats. It is hard to say how much without knowing the time commitment, difficulty of the work, aptitude and dedication of the parties involved. If it is not too much of a time commitment you may just want to give each 100k sats but if it is a big time commitment it is probably better to wait and decide individually how you would like to reward each one.

If they are volunteering, they are probably already happy to contribute to the project as they can. In the other side, you cannot expect much as if they were employees.

However, a nice thank you gift, a warm way to recognize their efforts and provide rewards every times they accomplish something is probably a better way to have them more motivated to pursuit volunteering.

What are you trying to build?

Unless it's a viable commercial project, I'd be careful announcing financial incentives too early. If it's just a passion project right now, you likely can't afford respectable money. So people with real abilities won't be motivated by your offers, and the people who are motivated by your offer may not be the people you want.