I'm planning a CFL grow and I have a question about my lights.

I have right now two bulbs I plan on using.
They are soft white CFLs.
It says they are 3 Way with low of 12w, med of 19w, and high of 28w.
Output goes low 600, med 1200, high 1750.
It says its used in 3 way sockets only, but it works when plugged into my worklamp I'll be hanging.

1. Will these lights be good for veg?
2. Is it necessary to change lights for flower?
3. Is there a specific CFL bulb somebody can recommend for veg and flower for me?
4. Does the general light schedule 18/6 for veg and 12/12 for flower work out best or is there a schedule that performs better? Produces bigger yield?

That's all the questions for now but there will definitely be more! Have at it!

Thank you