1. Are there any German rules/laws preventing AC?
No....don't be silly.
In my village of 4,400 people and roughly 2,250 residences....I'd estimate that 300 residences have heat-pumps/installed AC units (my dentist has AC in each room). I'd also guess that 1,300 residences have a roll-around unit (like I have).
2. The worst scenario?
You live in a roof-top apartment, and after the 5th day of 34-plus C....the place never cools off at night.
3. Are there any clothing required rules for bus/rail travel?
The past week....I noted a couple of guys on the train.....sport shorts/no-shirt. Gals? Tube-tops and sport shorts. There might be rules, but they aren't going to enforce them.
4. Weather for July?
Well....today peaks at 35 C (95 F)....chills off by 8 degrees C for 10 days.....then the 34-to-40 C temp returns....probably for two weeks. August is anyone's guess....might be a 3rd wave of 40 C.
5. How many public buildings have AC?
In Wiesbaden? Probably 5-to-10 percent.....mostly because of cost-factors. Schools? Zero.
6. Public buses having AC?
The label on the door says 'AC'....but lets be honest.....it probably works up to 32/33 C (93 F). Temp up to 40 C......don't go riding after 1 PM.
7. Why do more French people die from heat....than Germans?
Various theories on this.
Some belief that any French gal/guy dying (of anything)....if they die on a day of 35 C (95 F).....the doctor automatically labels them dead from heat....even if they fell down a stairway.
Some Germans believe that French nature to consume wine all day.....also plays a role.
Lot of BS, if you ask me.
8. Heat wave causing Germans to eat out 'late'?
Germans (majority) prefer to eat between 5 PM and 7 PM. Past month....this has slipped to a 8 PM to 10 PM deal.
9. Can you find a AC unit to buy?
I walked into a hardware store (OBI) yesterday....for some repair items. AC unit on display.....sign indicates next shipment in mid-July. Fan selection? Near zero.
10. If 38 C (100 F) were the norm for summer....say 30 days in June/July/August?
I would imagine mandatory-siesta-mandate (gov't talk going on) would occur. I also think 80-percent of homes would acquire AC units. I also believe the grid would be UNABLE to support the draw of power.