If the maximum distance between two weld increments or the end of the joint to the first increment is less than the pitch minus the increment length, all is good. There is no requirement to extend the weld to the end of the joint unless it is so specified by a separate welding symbol.
There is a good reason not to allow three welds to intersect at a common point. It is called residual stress. The stresses in the longitudinal direction of the weld can be treated as a vector. Three intersecting welds, three intersecting residual stresses. The resultant can be determined using the Pythagorean formula. Expand it to:
((a^2 + b^2 + c^2 )^1/2= d
Three intersecting perpendicular welds (think of a corner in a square tank) can easily exceed the tensile strength of the base metal. Where the thickness of the joint is such that it is highly restrained, it is not unusual to see a crack form where all three welds intersect. Higher strength steels, with an accompanying reduction of ductility, are especially prone to cracks were welds intersect.
Best regards - Al