Hi,
My wife and I did the belt on my v70 xc. The tightening thing we had was the automatic one. It was weird figuring it out before the job, when reading how to do it. It becomes clearer when actually doing it. From memory there are two motions at the same time, pulling the tensioner back and turning the spring. It is like pulling back a spring and then letting it sit against the belt and releasing it with the new pressure on.
I also fudged my marks and had the exhaust cam pulley one notch out. I used white out correction ink. I found the cogs didn't really move around during the job. Just my marks weren't quite accurate enough. I drove it for a day and the timing didn't fell very tight. It was all right, that evening reduced tension and turned the cog one notch back or forward.
Good idea to do water pump too. For me though the timing belt took a bit of energy. It was really hard to get it off at the bottom; under the crank pulley is a tight spot requiring sonambulist stuff from the belt, twisting and pushing. But it does come surprisingly. That probably beat trying to get the crank pulley off.

If you don't plan to replace the cam seals, then you won't have to remove the cam sprockets, which means you won't need to use a cam locking tool. Just make sure that BEFORE you remove the old belt you have the index marks on the sprockets aligned to their marks on the belt cover, and that you use a sharpie to mark the crankshaft sprocket's relationship to the crankcase. (There seems to be a lot of confusion about the crankshaft sprocket aligning marks so if you make your own mark before removing the old belt, and do so with the cam sprockets on their marks, then there will be no guessing when you are aligning the new belt.

Watch this video:

http://www.youtube.com/watch?v=IK_zH8g8Fow

It explains the procedure with the type of tensioner that you have.

If you have an impact wrench to loosen the crank pulley nut, then great, do as the video shows. But if you don't have one at your disposal, I've found that you can remove the narrow plastic guard that runs under the crank pulley (between the crank pulley and the engine block) and work the new belt in that way. (The old belt can be cut in half to make it easier to remove.) That guard is held in place with one 10mm? hex bolt at each end.

I have not yet replaced a water pump on one of these engines, but I noticed FCP had a video on Youtube to cover that also.