Answer
(Fatwa: 897/847=D1429)
(1) It is undesirable to recite next surah by leaving only one surah in between small surahs, there is no wrong to leave more than one surah.
(2) Wudu is broken by urine dropping, so you should be careful to make wudu right so that no urine drop may drip when you make wudu or after making wudu. The way for this is that you should urinate a little while before salah and make it dry with clod, hanky or other things. If urine drop falls on pants, then the ruling is that if the drop is spread within 2*2, then it is allowable to perform salah while wearing it but if the drop is spread more than the area (as there is possibility of it if dripping continues), then it is necessary to wash the place or to change the clothes for performing salah.
(3) It is a major sin to miss salah intentionally. You should perform the salah you have missed before, it is obligatory to make up the missed salah. You must do qaza of them little by little by calculating them and get active to perform salah in future punctually. For cleanliness, you should study Behishti Zewar and if any suspicion comes to mind, ask it in writing.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband