We already have something like that. If you go to My Feed, any games you've interacted with recently but haven't rated will be shown in the sidebar instead of the featured games. Maybe it's not the most visible place, but it helps, and I rely on it quite a bit in fact.

Nice, but it would end up becoming an annoying spam. If you want to make sure about such a suggestion being delivered, try to plant one somewhere around the main menu in your game. I saw it already done and I think it works well as a reminder. Just a "donate" button, next to "options" button, in a transparent location, if you think one of the screen corners is just too obscure. Donations work on the basis of higher ethics, while a lot of people were not properly introduced to a such. I started to understand it thanks to the Linux social environment, but the point is, even if I do not donate or even if I say nothing at all, the developers will keep doing their job, because they can estimate their value on own behalf. If you quit because I did not donate out of free will, you prove me right the skeptic, that it does revolve around money. In such case, [b]Steam[/b] should be your option. [b]Steam[/b] took the other way in their policy, as they would rather wrangle with refunding all those masses of people the pre-paid purchases, rather than loose some turn going around, but maybe this ought rather be said about the developers who go [b]Steam[/b], with what expectations. Because [b]Steam[/b] also has "free-to-play". Personally, I like to wait sometime after trying out a game to see how much of a footprint has it left in me. If nothing of estimated worth remains shortly, I am either unwilling to donate or will donate very little, the latter in case all I remember is that the game was big fun for a brief while. Now, if a game makes impact, I will then try to evaluate it with some simple rule of thumb: "excellent /good / fair", which would then determine the step of the height of donation. That is the plan, at least. But I believe you do not expect to make tons of money if you allow "free-to-play", do you?

For the rating, I almost never rate, but leave comments instead.

Look, I do not really think you can find joy in what you do, if you feel that what you do enslaves you, threatens you or otherwise brings upset. If you want to start investing in doing what you would like to do, expecting return in revenue, maybe you seek a new job, not a hobby.

Gamemaking as a job, is called the digital interactive entertainment industry and the industry, this is a different topic.