Set your native resolution to what you play at. Downscaling twice will result in even more quality loss (like copying a copy of a VHS tape). You want to use the dropdown downscale in Settings to scale the entire post-compositing frame down, it maintains more image quality. Downscale method is mostly a personal preference thing, performance difference between Bicubic/Lanczos is almost nil.
Post a log file, from the Help menu. Just 'Upload' and post the link here.
2500kbps is actually higher bitrate than is advised. There must be another problem (using NVENC/QSV/VCE, x264 Superfast/Ultrafast, random tutorial advanced x264 settings, or just a game that's very encoding-unfriendly). The log file will help us track it down and give more specific recommendations. Also, an example of the type of game(s) you intend to play.
720p@30fps, 2000kbps, x264 Veryfast (or lower) is the 'golden point' for non-partnered Twitch streamers.
Nexigen, I took a look at your thread. Your problem was not difficult. It may have been bypassed because a quick search of any prior blurriness thread would have put you on the right track; namely, downscaling and lowering your encoder preset. You can't run 1440p on 2400kbps Superfast. Even 720p Superfast needs more. Same remedy as above; 720@30, 2000.
