Pronouns in main clauses/subordinate clauses?

[blissful]

Hi

Are there any rules that say whether the pronoun should be placed in the main (independent) clause or subordinate (dependent) clause?

Should John be placed in the main or subordinate clause? What’s the difference?

1)While John was running after the snatch thief, he tripped over a stone and fell.
2)While he was running after the snatch thief, John tripped over a stone and fell.

Should John be placed in the main or subordinate clause? What’s the difference? What’s the difference in meanings between the past perfect tense and past tense for these sentences?

3)When he had finished eating, John got up from the table.
4)When John had finished eating, he got up from the table.

5)When he finished eating, John got up from the table.
6)When John finished eating, he got up from the table.

[5jj]

Are there any rules that say whether the pronoun should be placed in the main (independent) clause or subordinate (dependent) clause?
There are no rules, but the meaning should be clear.
[...]
1)While John was running after the snatch thief, he tripped over a stone and fell.
2)While he was running after the snatch thief, John tripped over a stone and fell.

Should John be placed in the main or subordinate clause? What’s the difference? There is no real difference.

What’s the difference in meanings between the past perfect tense and past tense for these sentences?

3)When he (had) finished eating, John got up from the table.
4)When John (had) finished eating, he got up from the table.

There is no real difference in meaning.

'Snatch thief' is not a term used in BrE. I did not know what it meant until I checked here Snatch theft - Wikipedia, the free encyclopedia . I am not sure what we'd call this type of criminal.

[blissful]

Hi
Suppose there are two clauses in a complex sentence.
The question is “How to decide which idea or information goes into the main clause?
The more important idea goes to the main clause?
The less important point goes into the subordinate clause?
Any guidelines, please.

[5jj]

Any guidelines, please.

No. It's a matter of the writer's/speaker's feeling.