🚀 go-pugleaf

>Q #1: is this method "normal" to generate EPS files?

It sounds reasonable.

>Q #2: is there any Log for errors and warnings of Illustrator as PS Script parser/editor. 

No. Illustrator is a very bad tool for this purpose. Firstly, there
are no error reports. Secondly, it does not handle the entire
PostScript language.

You should test EPS files by using them as intended:  PLACE them.
Then PRINT them to a PostScript printer; or Distill.  If that works,
they are valid.  If not, you have a PostScript error.

You can use Illustrator to Place, but be sure the LINK box is ON to
stop Illustrator trying to interpret.

On the other hand if your design aim is to make EPS files that
Illustrator CAN open, because that is your project requirement, you
have a difficult task. You have to first make valid EPS, then discover
(undocumented) the subset of PostScript that Illustrator understands -
and bear in mind it changes at each release.

Aandi Inston