It all depends on the project, my little experience has not come across such a long time participation of 8 weeks.

If you have started early in your bounty then you will have higher stakes that will give you more coins especially if your bitcointalk forum rank is a hero or legendary. I have earned a good earnings when I joined a bounty that covers a period of 10 weeks. But always remember that doing a bounty is a risk because the ICO has to reach softcap to be paid.

Probably yes. Because the longer it is, the lesser tokens to be receive. Additional weeks means additional division of tokens. But if the allocation is high, it is actually good because you will earn additional tokens .

If a bounty lasts for 3-4 months, then you don't have the freedom to participate in any other campaign during this period (at least for the signature bounties). A few months back, I was participating in a bounty and when it was about to end the campaign manager extended it by another 2 months. And he did all this without increasing the bounty pool.

it all depends on the results of their ICO, regardless of the large number of participants does not guarantee a bigger income, many successful gifts despite making the campaign in a short time, it's just about marketing promotion. I'm not saying it's bad but long-standing campaigns often cut revenue allocations for their participants for unacceptable reasons.

NOPE, the thing that affects earnings is that the value of eth or tokens allocated to the bounty campaign is few or small, also if the participants participating are many , this will surely affect the equal staking or proportionate share in the reward

I think it needs to look at its distribution mechanism. If it can distribute rewards every week, then it is acceptable for extended periods of time. If it continues to be extended without giving any rewards, then I will give up its mission!

In my own experience since I started bounty campaign, it is true most times that the longer a bounty campaign is, the lesser the tokens or coins one will get . The reason for this is that when ICO is being extended beyond the normal time,  it gives room to absorb more bounty participants which ofcourse will reduce the quantity of tokens to be given to individuals. If at the initial stage of a bounty campaign 1500 participants joined, but over time the ICO was extended  and another 1000 participants were added to make it 2500 participants, definitely the allocated bounty tokens will no more be divided among the 1500 but among 2500 bounty participants except in some cases that the project has already placed  limits to participants they are taken even if the ICO period is extended. So, if you think you can still bear it, you can stay to finish the project.

I total agree with you, I don't like joining bounty that take a long time, if a bounty take a longer, the reward reduces because the longer the bounty waits, the more people join and the less the reward reduce, so the bounty I normal join these days, max is 8 weeks.