When the subject is a personal pronoun, can it be completely reversed?

No!

The subject is a noun and the predicate is an intransitive verb. When the adverbial moves forward, use a complete inversion sentence. For example:

Out rushed a mouse. A mouse suddenly ran out.

Here comes the bus. The bus is coming.

In came a stranger. Suddenly a stranger came in.

Then followed a terrible noise.

Now is your turn.

Under the big tree sat an old soldier.

If the subject is a pronoun that cannot be inverted, compare:

Out dashed the dog.

Out it dashed.