My guess is that either the yarn really isn't wool or the koolaid you're using contains a non soluble food coloring. Look at the label and tell me what the ingredients are. If it says _____"lake" then it's a non water soluble food coloring.
I have never heard of cashmere going for $150 an ounce. I've found it for around $10-30 an ounce. While I agree that alot of the cost of commercial cashmere comes from mark ups and whatnot, the high cost comes from the fact that an individual casmere goat produces only about a half pound of useable fiber a year.
About the boycott: There is still domestic cashmere from local farms and they are not in any way shape or form contributing to the dust problem.
Also, this I'm not 100% sure on so maybe someone here can verify or debunk, but I think that while there is a breed of goat called the cashmere goat, cashmere fiber can come from any goat as long as it's the down fibers and meets a certain fineness.
As for expensive, there are some fibers that make cashmere look downright economy. Vicuna goes for around $200 an ounce, and guanaco, buffalo (bison actually) and qiviut goes for around $30 an ounce.
While I personally do believe that fiber reactive dyes are so much better than direct dyes and normally suggest that people use the former instead of the latter, this time I feel I should do the opposite. Fiber reactive dyes need a high ph to work on cotton and it would most likely damage the wool. If you use the mx dye to dye the wool, you'd have to lower the ph by adding vinegar and it will work just like an acid dye: it won't dye the cellulose in an acidic state.
Direct dyes dye cellulose and just need salt and heat to work and won't damage the wool but they're not very washfast. A union or all purpose dye like RIT contains both an acid dye and a direct dye. The acid dye in a union dye is usually a levelling dye though, and levelling dyes aren't very washfast either.
If you just use acid dye on the roving, the viscose part should remain white. Some acid dyes stain cellulose while others don't, so there is a chance that the viscose may be stained then fade to white after a few washings. Either way, neither the acid dye or the vinegar will damage the viscose.
I have had problems with silk not dyeing evenly: it seems to need longer to soak than wool does, but it still dyes.
It sounds like you have a viscose fiber like rayon, tencel, or bamboo. Since it seems like the "silk" portions are not completely mixed into the roving but are in there as streaks, maybe you could separate a small amount of the mystery fiber from the roving being careful not to get any wool, and spin it into a short length of yarn then do a burn test on it.
Though it does look like there is a brake band for spinning scotch tension.
The scotch tension setup is a little different than double drive and its driven by the flyer and not the bobbin like a dd and has grooves in the front with the brake band going on the back bobbin. The joy of handspinning site determinedimprovisation posted above will do a better job of explaining than I can.
It seems like you should just be able to use the scotch tension kit on the wheel and just move the mother of all back enough so that it's aligned with the drive band.
The only issue I have is that you're going to have to put both loops of the drive band into the same groove when spinning and I think that the grooves on a scotch tension may be narrower than those on the double drive flyer.
It may work just fine with the doubled up drive band in the groove but you may have to undo the double drive band and tie on a shorter, single loop drive band everytime you need to use the jumbo flyer, and then tie back on the double drive band when you go back to the normal flyer. You could also keep the other band hanging off the frame I guess so that you wouldn't have to tie and re-tie but I'd be concerned that it could get caught up in the wheel if you do so.
Also, unrelated to the bulky flyer issue, but about the pictures: it looks like yours is set up a little weird. I think you have the drive band loops going over both flyer grooves and the brake band on the bobbin groove. If you want to spin double drive, put one drive band loop on one of the flyer grooves (the ones in the back) and one loop on the groove attached to the bobbin. When spinning with a double drive setup, don't use the brake band.
To spin scotch tension, double up both drive band loops in one groove and put the brake band over the bobbin groove.
Ashford has manuals online if that's any help: ashford.co.nz
If you or your sister do decide to sell the fleeces, add my name to the list.
As long as there isn't too much vm, the fleeces are well skirted, and there aren't too many second cuts or breaks, I'd definitely buy a fleece.
You could also look into sending some of them to a woolen mill to get them processed into roving since roving seems to be in a higher demand by handspinners than fleeces and that you can spin straight from.