Construction of a 600m long water connection line, any experiences?

I do not have a connection to the public drinking water supply at home (but rather a spring and a well). Now the electricity network operator has planned a new power line and offered me to lay a (private) water pipe in his trench. The water supplier offers me a connection to its public network about 600m away from my two-family house (from there my private water service line would begin). There are a few small challenges, maybe someone here has experience and can give me tips, for example on the following aspects:

[*]The energy network operator digs 80 cm deep, the water supplier usually 100 cm. I suspect and hope that 80 cm is frost-proof here in the Rhineland.
[*]The private line contains about 600l of water. How do I ensure a minimum flow rate so that the water does not stagnate in the pipe?
[*]The water meter is far away. If a leak develops on the 600 meters of pipe and I read the meter six months later, I can probably declare personal bankruptcy (luckily we also have no sewer and therefore no wastewater fees).
[*]The energy network operator is allowed to lay its lines on public land, I am not. What permission do I need (from the city) if I want to use the same trench? (yes of course I will ask the city)

I believe pressure will be more of a problem. We wanted to deviate from our node 49m away for cost reasons (about €500 per meter) and move to a "private route" of just under 150m. According to the water supplier, this would have meant an above-ground sizing of the pipes and peripherals that is not worthwhile in the single-family home sector. Ask again here whether the minimum pressure requirements at 600m are guaranteed and what pipe diameter they are referring to.

I think pressure will rather be the problem.

True, but not in the way you think. One of the first pieces of information from the supplier was "you will need a pressure reducer." The supplier delivers with 8 bar line pressure, I am a bit lower and would have about 8.5 bar according to his calculation, which would not be optimal for either my pipeline or my household appliances. My current pressure regulation (behind the well pump and the pressure tanks) regulates between 2.5 and 4 bar, so I should be able to easily manage that with my new line and have no problem.

That contradicts itself. Even if you are 5m deeper, your pressure loss on the 600m long pipe would be 0. And an extension from 50 to 150m is supposed to be outrageously expensive? DN25 100m costs 129 EUR, DN50 costs 565 EUR. Well, that's four times the price. But the remaining work stays the same. The excavator doesn't care whether it digs the trench for a DN25 or a DN50.

you probably mixed up two lines (from and me)?

I focus on the contradiction that your two contributions clearly show.
150 meters instead of 50 meters is not possible there because it is insanely more expensive...
600 meters is no problem and there is hardly any pressure drop, even a pressure increase.
Because already with a DN25 and 0.5l/s the pressure drop is "only" 5.4 mbar/m. That reduces drastically again with a DN50 and honestly. 30 l/min is already quite a lot, a normal showerhead uses 12-15 l/min.

But no pressure drop at all is also just smoke and mirrors. With a DN25 and 600 meters at 0.5 l/s it is actually 3.24 bar.
Are you really located about 40 meters deeper? Or was something larger assumed?