Regarding Balkan Super League, we travel by bus. Getting to Turkey takes cca 22 hours but we combined it with May 1st holiday so for most it was a fun field trip. Actually, getting to Vitez through Bosnia was a bigger pain subjectively!
We don’t bother putting up websites when Facebook pages are much easier to maintain and people see stuff on Facebook anyway.
Serbian domestic league as you said is three groups: A are good teams from Belgrade, B are developing teams from Belgrade and C are three teams in southern Serbia. Last year I believe we played each other twice in the spring. We won group B and Nis won group C. Nis went through and played in A. We played Leskovac from C and Kangaroos from B winning League 2.
On top of all this we all play in the Serbia Cup, teams from group A visited Russia, and there is a Nines in Budapest in the summer. We play friendlies with a team from Montenegro.
Bare in mind that when the national team plays, players from group A are playing for Serbia. Unlike Aus, 20 men from three teams means that a large percentage of serious players get 5 more good games.
I’m sure I missed something, but it should give you the right idea.