I shall try to answer the given questions.
Quality of vowel reduction
There are two stages of reduction. First stage is in the syllable before the stressed one, in the absolute beginning and in the absolute end. Second stage is in all other unstressed positions. Here is the correct table (by Petersburg's norm, Moscow's is a bit different)
Stressed - 1st stage - 2nd stage
After a non-palatalised consonant
а/о - ^ (sound similar to а but with middle up-going of the tongue like in о) - ъ (sound like shwa); э (sometimes written as е) - ы - ъ; ы - ы - ы; у - у - у;
After a palatalised consonant
и - и - и; у (written as ю) - у - у; а (written as я)/о (written as ё)/э (written as е) - и - ь (another reduced sound a bit similar to ъ but pronounced close to teeth like э).
Pronunciation of е that stems from ять does not differ from pronunciation of е that stems from е for a long time.
Palatalisation and assimilation is another topic where Petersburg and Moscow are different in pronunciation. According to Petersburg's norm, there is no palatalising assimilation actually at all and there is no sound [ж']. The word дождь is pronounced [дошт']. Group зм always has non-palatalised з, the opposite is a dialectical thing.
Pronunciation of г is implosive (not fricative, as in Southern dialects and Ukrainian and modern-Greek languages, although it may be fricative in words like ага, эге, мгм, угу) voiced (unless in the position of absolute end or before a voiceless, in which cases it becomes voiceless itself) guttural sound ([бох] instead of [бок] for бог is old-fashioned and marginal, and then there are words лёгкий and мягкий and their derivates which have [x] not [к] before к and sometimes ч, but that's all), pronunciation of в is a voiced pair for ф, pronunciation of р is bilateral.
Stresses are directed by special dictionaries of stresses. For the word звонит it is on the last syllable, for the word торты it is not.