Dear Saugata,
thanks for writing. It has been long time to see U or some posts.
We all understand that U are helping the forum but U have Ur own army
to care and feed :-)

Now about Ur points:
1.& 2. We would never ask U to divulge Ur commercial secrets for FREE!
3. I have yet to commence the exploration of PIC. As I told U I am
doing all prokects in other world but ultimately it is a 8bit and uC thing.
So just nomeclature changes but basic things are same. I find that ATMEL
has also put up ARM type which are just as good as PIC and I don't have to change the assembly language. But sure will ask about PIC in few days after
finishing old projects.
4. I am also thinking about same PIC16F73 but I think other 676 has more PWM outputs which can of great help.
6.Ferrite transformer design is no big deal if U have designed iron core one.
There are many websites which have actual examples.Also if U can convert
48V to 300+ volts then 12-24 V to same is also not differrent. Just have some
more conductors and that helps for high frequency. For example I had make
primaries of 11SWG but instead I used 2 conductors in parallel of 14SWG.Nice thing about ferrites is that U need only few turns as turns/volt are as much as
40times less.
7. am hoping to know what 'new technology" U are talking about. Surely it will be very interesting for the thread of "sine wave inverter"
8. U have correctly stated the position of fast and slow turn on. Everybody
has to make decision about switching losses and surge supression and cost off higher voltage device. As far as Bridge drivers i hate those and I rely solely
on pulse transformers or opto couplers.
regards,
psdayama