You arent going to overload the cable, they just usually only put 3 connectors per string to reduce clutter, it can support wayyy more, especially if they are just fans, fans draw very little power compared to most components. Its perfectly fine to daisy chain all your fans together, it will still draw less power than a high speed hard drive would.
as i understand the psu doesnt limit the +3.3v & +5v per cable does it?
for the this kind PSU, can i connect unlimited drives, fan componets?
without reaching the combined load of the +3.3v& +5v ?