A few sentences to correct...

Hello,
I am writing a few essays and I have got a few doubts..I would be grateful if you checked the following sentences:
I am writing an announcement about the change of a classroom:
Our lesson will be/is going to be in the classroom number 13...(I would say will be)
Mr Wellington will/is going to teach us...(is going to?)

A letter about a thing I have forgotten in sb's appartment:
When I returned to France I remembered/reminded about my notebook..
(if both are possible, can we say remembered sth, without preposition?)

Things had gone wrong recently. (It's a narrative, i am using past tenses,can I use the word 'recently' meaning not long ago but in the past?)

I got off at the nearest bus stop

I was the most frightened person (in?) all over the world at/in that moment.

At/In the same moment....

My name is Tom and it has been/was me who has given/gave you a ticket
(if was is ok, can we say 'it was me who has given you..?)

I have helped/ helped you because you are very friendly.
(can we combine the past simple tense and the present simple or we should use the present perfect?)

my boss'/'s son (if boss's is correct do we pronounce it as /boses/?)

Pollution has the most/most impact on our environment.

means of transportation can take a lot of people at once/ by one time.

Scientist check various chemicals, substances and medicines before they are/will be exported to shops

health is on the first place but why do animals have to be in pain for us?


Thank you a lot for your help!
Annie