TUPARKA120 Pcs Waxed Necklace Cord with Clasp Black Necklace Cord for Necklace Bracelet Jewelry Making

Will a pendant or bead with a 4mm hole be able to be threaded onto this cord? Can either end of the fastener/clasp be removed to thread a bead with a

Is the cord 50cm with an extra 5cm extension (55cm total) ? Or is the total of cord and extension 50cm ?

Will a bead with a 4mm hole fit on this ? If not, is part of the fastener able to be removed to allow a pendant or bead with a smaller hole to fit ?

I want to use this with a pendant that weighs almost a half ounce. Will the clasp be strong enough?