As far as preferring the use of local words - or made up words based on the current language - it's something you find in many other countries/languages other than the ones you mention. Or tell you more, some of their languages did not change for centuries thanks to or because of their prolific written tradition. Everything proves that English doesn't have to be present within every language.
I agree they could have just made a silent transition without making a bill and imposing fines, but in the end the decision doesn't sound very controversial to me.
Italian words must have a gender, there is no neutral. Computer, mouse, touchscreen and touchpad are male. Power unit is female even if its Italian counterpart alimentatore is male: il power unit sounds bad, la power unit sounds good. Motherboard is female and its translation scheda madre is also female. Bug, bit and byte are male.
The rule is that loan words enter Italian with their singular form and they don't change at the plural. This might have funny consequences.
Medium / media (radio, TV, etc) entered Italian from English which got them from Latin. The plural of medium in Italian is still medium and pluralizing it as media as in English and Latin is a grammatical error. Media is becoming more common as more people read them in English sentences, not because they are studying Latin :-)
Gender is decided case by case as the word fits better in Italian. Medium is male (il / i, un)
And indeed if you say "calcolatore", I interpret that as the calculator app (or any small math-only calculators used in school)