502 acid spellpower, or 487 force spellpower, depending on the gloves. I suspect others can get their totals higher, but I haven't been able to farm 5-piece LGS or slavers sets lol (and I most likely wouldn't even if I could.)
The Rock Boots are definitely competitive with CC corrosion (even better, actually), if you can find striding/speed elsewhere. Using striding augs (or crafted striding) really isn't advisable until 20 when you hit max striding, considering how far behind the curve both systems run from lootgen speed. Boots of Corrosion are also not bad, but they'd quickly fall behind (the heroic boots have Corrosion +48 at ML5; CC has 47 at ML3 and 59 at ML5, and the gap just gets wider from there; Epics are +90, which you can craft at ML14, while crafted ML20 is Corrosion +111... and again, the gap quickly widens.) If you have the ings to craft at least T1 Rock Boots at every level (and preferably T2 at L11) *and* have a way to competitively boost your runspeed, Rock Boots are definitely extremely viable when doing acid arrows (won't do a thing for force arrows, of course).
And having logged on and looked at my enhancements... I took out Dispelling Shot, Banishing Arrows, Smiting Arrows, Awareness, & Mystical Archer, as well as Favored Defense & Extra Enemy from DWS, and put the points into Head Shot, Stealthy (for the sneak attack die), Increased/Versatile Empathy (2 points in each, for the Positive spellpower), and also only 2 points in Favored Hunter), & Horizon Shot. Extra points went towards Harper (Agent of Good/Enchantment) and Dwarven Toughness/Constitution (to even myself out). Oh, and Shatermantle Shot, mostly for the +3[W] but the SR reduction is nice.