Stick with Crane IMO. Seamers can be Edwards, Berg, McClaren and Ervine can bowl as well. Ervine should be recalled IMO as he will score quickly if he stays in which is always a good thing.
I guess there's also the option of combining the two selection issues together, and replacing Crane with Ervine. I'm not sure it's a particularly likely option, given that Ervine and Dawson would be batting 7 and 8, and Berg and McLaren at 9 and 10. Not that batting depth like that is a bad thing of course, especially at the Riverside where just an extra 20 runs can make all the difference, but it's just not at all common - and probably not necessary. I wouldn't be advocating it.
I wouldn't be at all surprised if Crane does keep his place, but you certainly wont be finding Durham play an out and out spinner. Onions, Rushworth, Hastings, a fourth seamer of their choosing (often Harrison this season, but I think he might be injured), and Collingwood. Borthwick (and Pringle if he plays) will probably hardly get a bowl.

