Is there a backup plan? Not saying that relying on donations is impossible, but realistically there is a very small chance that enough donation will flow in continuously.
Your question honestly got me thinking. If everything goes completely sideways there are a number of shuttering options I can think of.
One is to turn off any new uploads, and just serve the existing content, presumably the bandwidth on old content would be much lower - until some sustainable plan can be devised.
Last resort is to approach the ArchiveTeam mentioned here to see if and we could to setup a maintenance service.
To your side note, yes, I want to promote it on Reddit, as soon as I've added a few more features - like donations.
As a sidenote, reddit is (was?) the one of main user of imgur, however https://www.google.com/search?q=%22haasie.com%22+site%3Aredd... yields no results - maybe it is worth to promote it there also.