Regarding SP/RP eligibility, I went through the last 6 seasons of team IP totals at the MLB level, and it looks like most years cap out around 1450, with some outliers reaching as high as 1475 IP.
In our fantasy league, this year the owner with the most IP was JR, with 1409.
Seems like we should be able to set a cap 1400-1500 IP and have a really safe ceiling that would prohibit obnoxious levels of streaming. IP cap could be adjusted over time if we find it's set to high or low. Does that satisfy those concerned with SP/RP shenanigans?