What is the ruling on washing hands with water and soap before washing the face during ablution, in light of the coronavirus crisis, given the skin problems it causes due to its repetition for those with urinary incontinence? And how is ablution performed correctly while ensuring that water does not enter the pharynx when sniffing during fasting?

You must wash your face correctly and normally during ablution. It is preferable to use your hand for this. You should not exaggerate in sniffing water (instinshaq) if you are fasting. If you emulate someone who rules that it is sunnah, there is no harm. If you suffer from incontinence (sals), perform ablution for each prayer after its time has begun, and pray as many obligatory and supererogatory prayers as you wish until the time for that prayer expires.