Usually such alkaline soil is a poor starting point. It is a constant and usually loosing battle. What is worse is that your tap water is probably alkaline also. The best thing to do is used a raised bed of good well-drained acidic soil and to irrigate with rain water. This way you should face very few problems and just have to periodically add a little azalea fertilizer like HollyTone. Using a raised bed isn't too hard. The azaleas have shallow roots, so the raised bed only needs to be about 12 inches high. If you have to use native soils, use sulfur or iron sulfate to make the soil acidic. My website at: Henning's Rhododendron and Azalea Pages has instructions on making alkaline soil acidic and making raised beds. Using rain water usually involves creating a cistern to collect the water coming down your downspouts. Some people just put a screen over a plastic 55 gallon drum and run the water into the screen. Then the overflow is directed away from the house or into a drain. This should give you enough water to get you through droughts. Your plants will especially be sensitive to drought the first year or two after you move them. Good drainage is mandatory. They need moist well drained soil. Poor drainage is very bad. The first symptoms of alkaline soil is chlorosis. That is when the leave turn yellow between green veins. This leads to malnutrition and eventual starves the plant of nutrients. And finally, don't forget to mulch. This keeps the roots cool in summer and protects them in the winter. It helps conserve moisture during dry spells and prevent frost heave in winter. Some other good websites are: Missouri Extension North Carolina Extension (pdf) Home & Garden TV Rhododendron Society of Canada Here is a link that might be useful: University of Nebraska Extension site on azaleas

It's too HOT for clothes. LOL! ;) Unfortunately, it just doesn't look good for the Hoya. I think now that you should cut it way back to reduce stress on the roots, and then use all the cuttings to start new plants. As you know cuttings rooted in a solid medium have less brittle roots than plain "water roots". My earlier thinking of cutting the roots back and regrowing in per/vem was to encourage non-water roots to grow into the medium. You will need to stress the plant with a "controlled drought" for this to be successful. If you want to try this, 100% perlite dries out too quickly, 100% vermiculite stays water logged too long and becomes anerobic. There are some good starting mixes available at any nursery--usually some combination of perlite/vermiculite/sand/peat. see this Here is a link that might be useful: Transplant shock

You could try an outdoor Dutch Bucket setup Im sure they can adapt to soil but I would trim roots and cut back the plants doing that would be your best bet

I start my seeds in what I guess you could call a hydro setup,I use tobacco float trays made of styrofoam that float on a bed of water.I use peat in the trays so I do have some media that stays with the plants ,I assume you use rockwool or something of the sorts.I would say as long as you have some media attached to the main ball of roots I wouldn't worry about ripping a few of the "water roots" off. When I transplant mine to the garden from my trays I just grab them by the stem and yank them out and I have never had any transplants that didn't make it.Also I find as long as there is some amount of media attached to the roots they are more forgiving of when you plant them about not going into shock.I have planted mine in the heat of the day into a garden and they don't even wilt like a regular potted transplant would. I try to transplant mine by the time they are around 6 inches tall and by that time they already have roots as long as the plant is tall so compared to a potted plant with very short roots even if you lose a few roots you still have a huge advantage imo. To sum it up hydro starters transplant very well and will blow away and normal starter plant within 2 weeks of planting them in soil,I don't even start mine indoors I wait till april to start seeds outdoors and my garden always blows away every other garden around me before may. Hope this helps some even tho I don't use plastic pots in a 100% hydro setup I understand your concerns with ripping water roots and I don't think its a big deal to lose a few.