Whoa!!! You need to step back and review EVERYTHING. What you describe are radically bad symptoms. Did you have these conditions before the new rack? -- the clunk, etc. Disregarding everything else--your first concern regarding the offset wheel----the rack needs to be centered as far as turns lock to lock first--then you can pull the steering wheel (easy on a Volvo) to center it relative to the centered rack--now the tie rods can be adjusted for correct toe (after the camber is set). This procedure will be the LAST thing you do after--
Finding the source of the clunk and any other worn parts - 240 ball joints need to be checked by squeezing them as well as prying--how about the large A-arm bushings (the front small ones almost never wear out)--strut mounts, etc.
You need to check all the bushings in the rear too. Get those things straightened out--then you can do the alignment. And it wouldn't be a bad idea to swap tires with another car if any symptoms persist. -- Dave