Do urine or prostatic fluid drops after urination necessitate squeezing or straining, and do they obligate changing or purifying clothes, or placing something to prevent the spread of impurity, and is ablution (wudu') and ritual cleansing (istinja') required for every prayer, and does purity remain with the descent of these drops?

It is neither obligatory nor prescribed to squeeze the penis to expel what is in it. As for a light shake, we hope that will suffice. If urine gets on clothes, it is sufficient to wash the soiled part. The emission of drops nullifies ablution. If you perform ablution and nothing is emitted from you, then you are not required to perform ablution for every prayer. However, if drops descend after ablution, it is nullified, and you must perform ablution and purify the impurity. But if it is incontinence, then you perform ablution for each prayer after its time has entered and pray with that ablution, and what is emitted from you during prayer does not matter.