I can't comment on the teaching side of things - it would be a good idea to check into that before committing to a particular programme.
In terms of the Open Degree, SK277 will start its final presentation this October - they usually replace modules with a revamped version so it may well be replaced with something very similar, but you might want to check with them. A200 is also going to be on its final presentation.
The pathway you're suggesting for the history side of things looks like it would work, but on the science side SDK100 or K101 are suggested prior to doing SK277 (although they may just not have listed S111 there yet as it's new; it might do the job just as well), and S317 suggests that they expect you to be familiar with the content of S294 and S295 (both 30 credit modules, so you might want to think about including one it then in your plan), and possibly also S141 (or whatever replaces it; it's also at the end of its run) so you might want to find out how strongly they recommend people do that sequence of modules. You can effectively si what you like, but obviously if you jump to stuff at level 3 you haven't worked up to, you may find the work much more difficult.
Just a couple of things to think about - it's quite helpful to do a bit of fantasy degree planning at this stage, so you can see possible different routes to your end goal. (I had a spreadsheet!)