Could you please help me rephrase these sentences? Thank you.

1) Dad took the day off to come with me. (Rephrase?)
2) Don't take too much work on (rephrase?)
3) They took 20% off the list price.
They removed 20% from the list price (is there another verb I can use?)
4) It took us ages to get the children off (rephrase)
5) Fuel is taken on at Frankfurt airport. (rephrase)
6) He is a trained now and brings on new athletes.(rephrase)
The coach made an extra stop to take on new passangers. (rephrase)
7) thank you very much for replying to my last email.
8) Our school's secretary told me this morning she had received your application module. Our school's principal will probably sign it tomorrow.
9) I hope you'll forgive me for sending you so many emails. I have just been informed that I can include the detail about the subjects in the accompanying letter (which must be sent to our national agency together with the application module.)
I wish you all the best

took the day off = didn't go to work that day

took too much work on = agreed to do more work than was possible (time or ability or??)

They discounted the item by 20%.

to get them off = to send them on their way

fuel is taken on = fuel is put into the fuel tanks

trainer ... and invites new athletes to join the team

take on = let others get on (the bus or whatever)

7, 8, 9 = OK

1) My dad decided to take the day off to join me.

2) Be mindful not to overload yourself with too much work.
3) They deducted 20% from the list price.
They subtracted 20% from the list price.
4) It took us a long time to get the children to sleep.
It took us ages to put the children to bed.
5) Fuel is refueled at Frankfurt airport.
Fuel is replenished at Frankfurt airport.
6) He is now a certified trainer and brings in new athletes.
The coach made an extra stop to pick up new passengers.
7) I really appreciate your prompt response to my last email.
8) Our school's secretary informed me this morning that she has received your application module. It will probably be signed by our school's principal tomorrow.
9) I apologize for sending so many emails. I have just been informed that I should include details about the subjects in the accompanying letter, which needs to be sent to our national agency together with the application module.
I apologize for the excessive emails. I have just learned that I can include subject details in the accompanying letter, which must be submitted to our national agency along with the application module.
I wish you the best of luck.