"if glass crack it will straight away crack and not wait for 5 day later then crack" <= this not very true lor...it may be a hariline crack when shifting, then it worsen after you add rocks and sand into the tank. or maybe there are vibration from your place due to constructions that worsen the crack.
Dont reuse and save on the foam...thats the most important support for your whole tank and sump.
Marine tank is always much heavier than freshwater tank. so the stand may not be suitable for marine. the 2 thin metal support looks more like an addon and definitely will not support the weight of a reef tank. Mine easily double the width of those.