Holy cow Narf, how did you manage to extract all that information from that image? I pretty much saw only pixelated blurs! It took me a bit to identify all the pieces Great work! Also, you're too german... the 5% bonus is to avoid continuous controversies in court, which the administration could win or lose (and they don't want to even risk losing, as this would mean losing money). So they put the 5% reduction on the -real- measured speed, basically giving you twice as many possibilities to avoid it (speedometers are quite optimists).
Anyway, what I could get is basically what Narf found out: 41 is the minimum amount you can pay for speeding, and it applies between n +1 and +10 kph AFTER the 5% (minimum 5 kph) reduction. So 94 -after the reduction means 99(-0+0,5) before the reduction (5% should be 98,95, so 5kph applies). This also means your speedometer was at something like 105-110 kph.
The place is a narrow, very busy dual carriageway with no emergency lane, no room outside the lanes. Most importantly, that road is rightly considered dangerous and police is quite strict with the speed limits there. Knowing that road, that road is bad even for italian standards.
Since the car was a rent, they sent it to the rental company which sent it to you.
I can't tell you the exact terms of payment, though, as the picture makes the document unreadable.