0.035 is equivalent to ~$250, that's more than a full time salary in some low economic development countries. I wouldn't consider it whoring yourself out if that's the situation.
$250 is peanuts given the workload required for a single week of campaign. There are two options: 1) Manager is doing his job. 2) Manager is not doing his job. With such a low rate, the later is almost the case with 100% certainty.
For a small/medium campaign this seems like a fair amount.
No.
It is unlikely a large campaign is going to choose a new manager, so I doubt you've got competition to worry about yahoo.
There are examples of this. Take a look at the Waves campaign and their baboon CEO.
You have been already explained why. $250 a week = $1000 a month. This would give you a decent living in places like Poland (minimum wage being $548). A lot of people there would love to work at home doing that.