Newbie on Dm900 questions

After many and happy years with a DM800HD i move to DM900UHD...

I am on the beginning of configuration and discovery of this box and i had read contradictory things about some points.

I appreciate if someone could help me clarifying some points:

1. With 1 single cable connected to tunner can i watch different channel´s at same time (1 on Tv other on Pc, or recording 1 and see other)? I have Dvb S2x Ms tunner.

2. Barry Allen is the only Multiboot option (i use Meoboot on my DM800HD and never had been capable of install BA)

3. Can i watch 4.2.2 feeds?

4. Can i watch movies with subtitles (srt files)?

I had not opportunity to test because i am with a problem with my HDD: I have two partitions (1 with 400Mb and other with 470GB) and the only i can use is the small one... the other have the information: "Unsupported partition type". I know i need format the Hdd but i have no way to connect it to PC... There is any way to format the Hdd on the box?

Sorry for so many and basic questions... and thanks in advanced!!!

About point 4:

I fix my Hdd and i test the subtitles... Works ok but they are too small and very close to the bottom...

Is possible change subtitles size and position?

Thanks!!