well i somehow figured thing out, let me explain where i think may be problems and how i put thing together with sketchup (not professional approach but got it done).
Multiple points in same area : well i always tried to optimize and when it doesnt changed a thing i splitted that part of spline to other layer on i can get two good objects and not 1 faulty, this didn´t much worked.
Making extrude object editable gives separate depth of spline and caps, so even with connect like plugins i couldn´t get single fully connected object, that may confuse boole.
aand i got to the point where i could “boole” thinner text from caps of extrude of fat text, so that tunnel like parts i put together in sketchup by placing outline of thin text on face of extruded fat text, and did something exact like “extrude” in c4d, with a bit patience with manual cutting i put it together.
Thanks for patience ????