Some tensioners CAN act up or down. Others (the cheaper, single mounting. sprung ones) can't. I prefer the smooth pulley (up or down action) ones to the sprocket variety, but the one I had in the box won't fit to cowled drop out.
No, clockwise is clockwise, regardless of which way round...maybe I could swap a spring from a canti. However, I've not shipped a chain on the back in a long time. I guess it would be critical if using conventional ramped cogs, but I have a BMX one. The chain entry angle is similar to that of a derailleur, and I've never had a skipping problem on one of those either.
I think the chain skipping problem is one that is exaggerated. The only time I've ever lost one is when landing a jump.
with a der. and gears you prob wouldn't be putting as much strain on the chain as when you SS on the very steep climb as you would prob have switched up a few gears anyway and even if it is exaggerated (not sure) the thought of the pain as your gongs rattle on the top tube would make me go down the "better safe than sorry" route. Mind you, if it works for you they fill your boots.
My Kona King Kahuna and Moots Rigormootis single speeds.
The lower pic is as the KK is now with the following in titanium; Syncros seatpost / clamp, stem, pedals, CK Headset, stackers, Black Sheep forks, ti railed flite, Hope ti front hub and a sprinkling of ti bolts. Also sports Avid Ultimate brakes with Flak jackets and 517 ceramic rims, rear hub is a WI ENO eccentric with WI 16t freewheel, Middleburn RS3 cranks with Surly 36t stainless chainring and ti self extracting bolts. Easton carbon monkeylite risers with ODI Ruffian lock ons.
I haven't used it for months as I'm always on the Moots ss these days, so I guess it may be in the classifieds as soon as I can be ar$ed / have time to strip it down.
All that's changed on the Moots Rigor is some new tyres, just fitted this afternoon.