Questions on Drones, Autosoft and OS Options

[Mike_Black]

Hello

My first questions is about autosofts.
Do I need to buy them once and do they run on my Commlink, so all Drones can use them?
OR
Does each Drone needs his own Autosoft (e.g.: I have Clearsight for each one seperatly...)?
If so, do I need to buy it once (and then copy it)
OR
for each drone seperatly
OR
perhaps for each different size-class of drones (idea is: a microdrone does not have that much RAM as a large drone, so the Autosoft has to be programmed differently)

Second question is on OS:
Each drone has device rating 3. So they have Respons=Signal=Firewall=System=3 (p.213 device rating, first paragraph, last sentence)
On the other hand it says Pilot = System, which in the case of the core rulebook means each drone has System 3 (perfect match to device rating).
When I now want to update this stats (e.g. Response to 4) I need to buy Response 4 for 2000 Nuyen and can't upgrade buy buying 1 Point Response, right?

Third: If i want a nice commlink (same as the sample drone rigger) with "device rating of 5", do I need to buy an expencive Transys Avalon (Resp4/Sign4 - 5000Nuy) and than modify it to Rating 5 OR can I just by a simple Meta Link (Resp1/Sign2 - 100Nuy) and then modify this.... Same to OS?

Thanks for your help
Mike