Be sure to have a plan on how to select birds for mating, before you start. Odds are you will quickly find yourself breeding pairs where neither has the full complement of traits you want in final product.
Those traits will be easy to verify they are being carried forward. Owing to number of traits, you will still have trouble ensuring at least a few birds carry most of those traits. The more traits you are carrying torwards the larger size with linebreeding back to your bigger birds, the faster...
Do you know which silkie traits are dominant / recessive relative to alternative alleles your large fowl carry? That will give you insight into what alleles you will need to be taking care to restore by either crossing lines or doing some targeted inbreeding. The recessive silkie alleles are...
Yes, back-cross immediately. You can do the crosses between back-crossed lines later. I would create a diagram showing breeding plan. Then create a list of attributes you will select for. Odds are you will have trouble getting individuals carrying all the silkie traits each generation. You may...
This is a more doable project. You might be able to start line breeding back immediately rather than breeding the F1's to each other. You will still have to raise a lot more chicks than you will actually use for breeding each generation.