I haven't reviewed the full exchange yet, but from the discription offered I think you are overworking your computer or router. Bitcomet is a lot more than just a bittorrent client and you are running 3 clients each of which with hundreds or thousands of connection each cycle, then you also have the other functions available only in bitcomet. You can disable all the aditional functions and make it just a bittorrent client, it would be as good as any other client, but not exceptional but the choice is yours. Just keep in mind that some of bitcomet's advanced features like Long Term seedingare coded to not use bandwidth when resources are low so this could be it's designed function. I suggest try running bitcomet by itself, it will use more cpu time if it's not forced to throttle, but won't use more than is available. Same with bandwidth.
Check what it can do when you give it all the resources it needs. You may find a torrent that has been dead for a long time finally finishes for everyone because you joined with bitcomet. You may also see high speed servers to help you speed up the torrent for other users. Or if you want it to run with less processes and less connections then disable the items in "services" category and it will do only bittorrent.