Yes but English has been compulsory in Polish schools for quite some time now.
English isn't obligatory. A foreign language is obligatory from the 4th class, and a 2nd foreign language from the 7th class. Apart from that, there's no restriction on what language, provided it's available as a Matura subject.
I know plenty of people who did language pairs such as French/German for instance.
I understand that the quality of teaching of Russian in small towns/villages is far better than the quality of teaching of English.
Without a shadow of a doubt. English was (to the best of my knowledge) usually only taught in the best schools in the PRL-era, and there are still plenty of Russian teachers around.