Q.1.Can we wear swimming shorts while swimming, as it does not cover the whole Sater?,

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu 'alayhi wa sallam, is His slave and Messenger.

It is obligatory on every Muslim to cover his AWRAH (Those parts of the body which must be covered. A man must cover his body from navel to knee and a woman must cover her whole body.) It is likeable to cover it if he is in darkness or even nobody is there, as mentioned in Prophet Muhammad Hadith: Bahaz narrated from his grandfather who said: “I asked Prophet from whom should we conceal our private parts and to whom can we show? He replied: “conceal your private parts except from your wife. I then asked: “Apostle of Allah, (what should we do), if the people are assembled together? He replied: if it is within your power that no one looks at it, then no one should look at it. I then asked: “Apostle of Allah: if one of us is alone, (what should he do)? He replied: “Allah is more entitled than people that bashfulness should be shown to Him. [Ahmed, Tirmazi, Ibn-maja.] A Muslim should fear Almighty Allah and should not adopt western culture as they make some specific places where a person may nude himself or he would stay with undergarments, which barely cover the private parts. Whoever likes to swim he should wear the dress that covers his AWRAH.

Allah knows best.