seclusion with a non-mahram

Q: I have three questions:

1. An apa teaching in a madressah, sometimes she doesn’t have a lift so a Moulana picks her up with his small daughter in the car. Is this permissible?

2. From my work to the train station is approximately 1km, the cleaners ask me to drop them off

a) If there are 3 females and only and me is this permissible?

b) If a male staff member accompanies me?

3. In my office there is a like window separating two section, the section is regarded as the buyers office and my office is regarded as the computer room, May Allah make my magfirtat we have 3 males and one female sometimes the other 2 males go out, is it permissible if someone is still in the buyers office or is it necessary for me to leave the office till they return, are the offices regarded as one since there is no door or hindrance to go from the buyers office to the computer room?

Q: I am a married male attending a course over the weekend as well as a married female who lives in my street and belongs to the same running club. The course location is about 10km away from our houses and she suggested we travel together on Saturday and Sunday to and from to save travelling cost. Is this advisable?

Q: A person works as a career and visits elderly people to give them medicine and make sure they take it. Is it permissible for him to visit elderly women for this purpose? Or will it be considered khalwa despite them being elderly?