Few questions about upgrade/install

Dish is sending out an installer to upgrade my receivers. They are not sending me the receivers, the installer is supposedly bringing the brand new receivers. My questions are:
Should I call up and ask for all my receivers to be deactivated before the install? (Because I don't want to add a bunch more extra receiver fees--even if pro-rated for a day or two).

Will the installer want to activate all my receivers before they leave? Will they know to make sure the old receivers are deactivated first? Again, I don't want to have a billing mess to deal with. I would actually like to not deactivate my old Dishplayers (for 1-2 days), because once deactivated, you will not be able to play (for more than 10min) stored recordings--and I need time to transfer them off.

I'm having all the DVR and phone line fees waived (grandfathered) and am wondering if doing any kind of activation (automatic? Manual? Calling a CSR) will risk losing those waived fees.

Can a DPP Twin feed a DPP44 switch (only need 110&119) and then I can have a max of 4 dual tuner receivers fed off that switch with 4 single runs of cable? (with the splitter at each receiver end)

Finally, if the install is taking too long, can I just 'sign off' on the install and finish it myself? I wired/installed the existing installation from years ago and know how to hookup the equipment--but dish insisted on a installer coming (I think to be extra nice, since I had to deal with the Exec. Resolution dept twice!)

Again, this is mainly to ask if there is anything to be careful of in activating these receivers and somehow 'triggering' phone-line/dvr fees to be added. (Executive resolution waived them all for me--again because of the forced receiver upgrade)
Thanks for any info!