First, keikis cannot possible kill the parent plant. Many plants normally cluster from the base. This is their normal growth. They would not have evolved to do this unless it were beneficial. Excise this idea from your plant knowledge, and don't think about it again.
I suggest you read about every plants before buying. The
Internet Orchid Species Photo Encyclopedia (IOSPE) is the place to start for species. For hybrids go to
orchidroots.com and then look up ancestor species. Finally, use the maroon menu above and the Search function to see how others here have grown a plant.
The eBay listing is gone so I can't see the plant.
I sometimes but not always repot plants on arrival, depending on the condition of the medium. Others here repot all plants on arrival. There are arguments both ways.
Semihydroponic culture (S/H) works great for Phals if your growing area is warm all year. Is it? Mine is, but a lot of people growing in cold-winter areas of the US keep temperatures fairly cool in winter, and this isn't good for Phals in S/H.
The time to put plants into S/H is when they are making new roots. Phals typically make roots throughout warm weather. If your growing area stays warm, and the plants looks healthy, now would be a good time to move it to S/H.
I recommend you read all about S/H on the First Rays Web site before trying S/H, because the Web is full of misinformation about S/H. Ray invented the S/H method we use.
Yes, I always practice new things on cheap plants, the cheaper the better.
Finally, schilleriana is not hard to grow.