If you know a programming a little bit (or better :-) you can use your skills to write simple parser. The best choice is to use language like python and already finished module for GEDCOM parsing (like https://github.com/madprime/python-gedcom) It is really not hard task to strip all unused information from GEDCOM because it is plain text file. One can use text editing tools, but scripting is more convenient.

The removing of non-blood relatives is more complex because one needs to filter relations between persons in GEDCOM. It is also possible task, but will take more time that just removing unused info. This can't be achived by just iterating over file contents. But if you find ready module with traversing of family tree, you will be able to do it in several lines :-)

If you know a programming a little bit (or better :-) you can use your skills to write simple parser. The best choice is to use language like python and already finished module for GEDCOM parsing (like https://github.com/nickreynke/python-gedcom) It is really not hard task to strip all unused information from GEDCOM because it is plain text file. One can use text editing tools, but scripting is more convenient.

The removing of non-blood relatives is more complex because one needs to filter relations between persons in GEDCOM. It is also possible task, but will take more time that just removing unused info. This can't be achived by just iterating over file contents. But if you find ready module with traversing of family tree, you will be able to do it in several lines :-)