Still pretty much a noob at this game but to include research building along with libraries seems like it would seriously overpower the Writing tech, at least that early in the game, and depending on the difficulty level/AIs in your games, not do much to Alphabet either way. Alphabet is usually a trade-for tech unless you play on low difficulties with crappy teching AIs, where you have to do it yourself, at least from what I gather.
Here's my reasoning:
After Writing, assuming you have whippible population, Libraries aren't but a handful of turns away at most, and in cities with even one decent food source tile that's +7.5 science per city, while running as low as 3 pop to keep maintenance down and 0% slider to bank gold for binary research (which I recently found out about and works wonders!). Of course there are also the eventual bulbs (which I still don't fully grasp the strategy of, but I know it's done by players). It's a major way to survive expansion and still tech towards important things like Currency which will actually help fix your economy. At least that's the case for expand happy players like me who are still guilty of wrecking their economies without even warring in the early game. It's a less involved way than Oracle-ing into Caste System and running scientists that way, can be done earlier, and doesn't rely on winning a Wonder race.
Research building included that early means you could easily skip building the Library in the first place, and just grow the city and improve hammer tiles. It would defeat the purpose, I think. Or with high food+hammer spots, do both Maybe moving Libraries up to Alpha would be in order in that case? Or maybe having the option to either build science OR farm a Great Scientist is the kind of early flexibility you're wanting in the early game?
I think Writing serves its purpose fine as it is: Open Borders generates you some potentially better trade and is the first step to real diplomatic interaction before Alpha/tech trades, Libraries are a guaranteed early way to run scientists to keep your research alive under economic stress, and you can eventually bulb some stuff (just get Alpha first), especially if you're philosophical.
) so it might be impossible to tell what techs they have without Alpha.... and I skip it until time for Printing Press 
but player wants to work wealth to get research rate higher so.... its specific thing in game (most times for OCC or small empire and for early rush when can't get to Currency other way)
