Casey, I have no desire at all to put a damper on your interest in accuracy in English, but some of your questions are about things that would not worry the average native speaker. What follows is my personal opinion; others may not agree.
At one end of the scale of 'correct English' we have "his ball is throwed in a speed of 80 miles per hour." Here we have two clear breaches of the 'rules' of standard English:
1. 'throwed' is an incorrect formation of the past participle. Such mistakes are often made by native speakers who have not yet learnt, or are not bothered about, such slips; they may even be common in some dialects.
2. 'in' is not the appropriate preposition with '... a speed of...'. This mistake is normally made only by non-native speakers.
At the other end of the scale, we have things which concern style as much as grammar, and there are sometimes heated arguments about what is 'good' English. Here we are into the area of such things as the acceptablity of 'under the circumstances' - there are those who claim that, because of the etymology, we must use 'in'. There are those who argue that 'miles per hour' is wrong, because we should not mix Latin and English; we should say 'miles an hour'. Similarly, they say, we can say 'per diem' or 'a day', but not 'per day'. The topic of your question is in this area, in my opinion. Most native speakers do not worry about such things, and continue using forms that are completely acceptable to all but a few style gurus.
The gurus would not like "is thrown at a range of 82–87 miles per hour". Very few readers would notice anything amiss. In any case, If American sports writers are anything like their British colleagues, they will happily use words and constructions that make an English teacher shudder.
