Touring Drivetrain Dilemna
The replacement of the 9 speed Shimano road RD with a 9 speed Shimano mountain RD is fine -- the cable pulls are the same. You'll need to re-size (i.e. put on a longer) chain for the bigger cassette though.

As for the crankset swap, I think with the new cassette it isn't going to be necessary. In any case, the Sora FD-3403 (which is what you likely have) has a maximum front chainring difference of 20 teeth whereas you're asking for a difference of 22 teeth, so you're technically out of spec. Since its 2 teeth, you might be able to get by, but you'd have to try it and tune it to see if it works. You do need a Shimano road FD to work with the Sora shifters.