Pasta, especially dry pasta, takes a lot longer to cook and never tasted quite 'right' to me. It worked a bit better if you didn't salt the cooking water, which also lowers boiling point, but then the pasta was never seasoned properly in addition to not being quite right. I think that was my biggest gripe.
Pretty much anything boiled or braised took longer to cook. This isn't an issue for meats and fish because you just want their internal temperatures to get to 120-150 or so, and gelatin dissolves at just under 100 degrees.
But, starches and grains can get gummy if exposed to liquid too long, so sometimes cooking rice can be a challenge. I owned several rice cookers while living at high altitude, and they seemed to work out ok. -They would sometimes boil up really fast and boil over, so I would leave a towel on the lid to keep it down (I can recall seeing it literally dancing in mid-air on the boiling rice water once!) and retain more water. The final product was always good rice, white or brown, so no complaints there -just a bit of adjustment to using the machine. I knew other people who struggled with rice when new to town, though.
Casseroles with potatoes may need more liquid to cook thoroughly, if the liquids involved are watery. If they are cream & butter, the adjustments needed will be minor or nonexistent.
Baked goods needed adjustment, sometimes in really odd ways. I got hungry for popovers and could not make them work. I asked around, and none of the local chefs (or ordinary people for that matter) I knew made them and they were not on any restaurant menus. I worked on the problem for over a year, and then discovered that using a slightly higher amount of egg and a different size was the answer. Essentially, 4 extra small eggs instead of 3 large, as called for in my original recipe, was the secret. I have no idea why using the XS eggs worked, as I had tried adding more regular egg white and/or yolk and it failed. (and I know to only use fresh eggs) I was only able to get XS eggs from a local farmer who sold eggs at the flea market.
The real catch to all of this is that some formulas work well, like the baking powder adjustments given above, and others are approximate. I'd start keeping a journal and noting recipes and how they work out, so you have a reference for your altitude. (and humidity level, Santa Fe is pretty dry)
Enough rambling for now!

If you have any more questions, I'll try to answer as best I can!