Probably one of the best forum posts read in a long time.
Some additions...I've been live streaming for sports, corporate, and entertainment for almost a decade now and and really haven't seen any issues with Adobe Live encoder except when I hear from people who are using a Mac as most (good) live encoding started out for windows bases systems...Most hadware/and computer based systems are really just command lining adobe/windows media/ ect anyway. Where live encoding gets most glitches winds up in not having dedicated encoding card or sometimes 2( one to capture video and one to capture audio) though that is going way now and mostly can use one card...My Decklink card encoders have been rock solid for couple years now. If you need to step up the encoding then maybe using a Osprey card(about $1500)...these you can purchase license to do simulstream if you require different bitrates or need to stream same bitrate to multiple content delivery networks. They are built into most of the $15k encoders ala niargar
a/digital rapids so $500 computer and $1500 card can get you same performance.
Another issue though could be your content delivery network...Also if you are streaming rtmp but viewing m3u8 content then somewhere down the line the stream gets hashed for m3u8 and you should typically see delay(if you at live and then viewing web) up to a minute or so...rtmp to rtmp fmle you should see about 2-10 second delay...again delays are perceptual you in the room end user they have no clue. The only thing I don't like about FLME is that your pixel sizes need to be even numbers...so not totally true 16x9 settings when doing small size encodes and you will have to a height or width to nearest even number.
Also unless you are streaming to a Roku device channel that is streaming to TV 1080 2mb settings are overkill for streaming live...max it at a 720p, 520, 480, (which will help with encoding if computer choking) and cut the stream bitrate down to about 400kb/s-750kb/s for sports...play with that and what you think is acceptable for your needs. Corporate I don't usually stream more than 200kb/s 1) talking head not much backround re-encoding2) corporate network sweet spot 3) you doing smaller video sizes because you have webpage that has video and pushed synchronized slides (jpeg) in other frameset...soo video is maybe 320x240 or 420x270 ect...
I like the h264 recorder and light mix option..may build that out for one of my MMA clients...I would suggest splitting it's output to goto mixer then one to goto small confidence monitor for your commentators to watch and do their thing.