Sentence number 5 was incomplete.

I think I should leave out "in part two".

I urgently need you to have a look at these other sentences, too
1) I hope you can help me find a Scottish school which is interested in a partnership with our school.
2) In the mail I sent to Mrs. Marsh I meant "Scottish" and not "Irish" schools
In the hope you’ll forgive my oversight, I send you my best regards from Italy.
3) He advised me to contact you and your school since he believes Finland is more significant than England in relation to biodiversity and water.
Before mentioning our Comenius project (to you), I’d like to introduce both myself and my school to you.
4) As our preliminary meeting is very close, I urgently need to know if you would be interested in such a partnership.
Of course you could follow our preliminary meeting in a video conference (I don't know how to express it).

Yes, I'd omit "In Part Two ..."

2. comma after "Marsh"

3. I'd omit the second sentence entirely.

4. First sentence is OK.

Of course, you can keep up with our preliminary meeting by participating in a video conference.
OR
... you can participate in our preliminary meeting by means of a video conference.

Sure, let's review the sentences you provided and make any necessary changes:

1) I hope you can help me find a Scottish school interested in a partnership with our school.
Explanation: This sentence is grammatically correct.

2) In the email I sent to Mrs. Marsh, I meant to mention "Scottish" schools instead of "Irish" schools. In the hope you'll forgive my oversight, I send you my best regards from Italy.
Explanation: Here, we corrected the typo and made the sentence more clear.

3) He advised me to contact you and your school because he believes Finland is more significant than England in terms of biodiversity and water. Before mentioning our Comenius project, I'd like to introduce myself and my school.
Explanation: We rephrased the sentence to make it more concise and clear.

4) Since our preliminary meeting is very close, I urgently need to know if you would be interested in such a partnership. Alternatively, you could participate in our preliminary meeting via video conference.
Explanation: We changed the wording to make the sentence more direct and added an alternative option for participating in the meeting.

I hope these revisions help clarify the sentences. Let me know if there's anything else I can assist you with.