1) Майя вышла замуж за Андрею Шаховского (the nominative is Шаховскои)
ШаховскИЙ. Андрей Шаховский.

2) Я Маше звонила, но её не было
I called Masha but she wasn't (at home). It's a common form for this kind of sentences in Russian, and it really looks a bit strange ). You might also say "но она не была у себя дома", and other people will surely understand what you mean. But the native Russian speaker never say it that way

3) Друзья долго ПРОЩАЛИСЬ. прощались is a sort of.. mmm ... continuos tense in English. Frends have saying goodbye to each other for a while
And the second one is actually right. Попрощались means they have already done it, sort of perfect tense
Hope this will be clear enough about tenses )