How many more transactions per second will be possible with SegWit? On a percentage basis compared to the current theoretical limit how many more transactions per second will be possible after SegWit?
Will the answer to number 1 scale linearly with block size increases in the future?


Please exclude the impact of lightning or thunder networks for the purposes of my question.
Best estimates on effective blocksize with SegWit are 1.6-2.0 MB.

Current transactions/second possible are around 3 tx/s. Given that the effective increase is 1.6 - 2.0x, the transactions/second are also the same multiple giving us somewhere around 5-6 tx/s.

The second question is harder to answer. There's a reason I wrote "effective blocksize" since segwit transaction sizes are different. However a straight blocksize increase on top of segwit indeed would be linear.