Absolutely agree about OBP vs. SLG - and yes, OPS over-values SLG. I can agree that oWAR helps here - but then you get the muddiness that's contributed by dWAR, so I remain to be convinced about WAR overall. There's also the problem that WAR is a counting/cumulative measure, not a measure of productive rate.
This remains to be seen. It's certainly a small sample at this point - but Goeddel's current seasonal stat line is substantially worse than his line for the past four weeks; it's not at all clear to me that we should expect the rest of the season to reflect his current seasonal numbers, as opposed to his last month or so. Too early to tell.
As for prognostication - it depends on your timeframe, I think. Ben Revere could be expected to repeat his career line - for the next season or two (he's 28, his game is built on speed). Goeddel is 23; I don't know what his career averages look like, but they're likely better than his age 23 numbers will be. I know I don't have to remind you that age matters - a lot.
That said - no, we shouldn't expect another big score like we got with Odubel Herrera. Yes, he's at the age (23 last year, 24 this year) where prospects sometimes make substantial gains, but his rate of improvement is...well, kind of amazing. It would not be reasonable to expect Goeddel (or any Rule 5 pick) to improve at that rate.
Not to pile too much on Goeddel, but consider:
At age 22, Goeddel's numbers in AA (Southern League, Montgomery) were .279/.350/.433/.783. BB% of 9.0%; K% of 18.4%. SB/CS: 28/9, 76%.
At age 22, Player x's numbers in AA (Southern League, Jacksonville) were .282/.340/.368/.709. BB% of 7.2%; K% of 14%. SB/CS: 16/7, 70%.
Who is more interesting? Essentially the same BA; Goeddel slightly better at getting on base overall, with better power. Better BB rate, somewhat more strikeouts. Goeddel ran more, to a slightly better SB%. You pick 'em.