Obviously the actual content of each document will reflect the style of the particular lawyer who drafted it. But sometimes, re-inserting the commas which a lay person might use helps to clarify. But beware, it can also change the meaning from the 'legal' meaning. For example in a recent case involving patents the phrase "... the said body having a free inner bore holding a capacitive data link" was held to mean that the data link was held within the inner bore, and not held within the body as the patentee intended it to mean. This was fatal to the validity of the patent as a whole.
You mention synonyms. If these are truly separate words which mean the same thing, this may be deliberately done to impart a nuanced meaning to the different words. Normally within a legal document a word is deemed to have exactly the same meaning throughout. This aids both clarity and certainty. This is also the reason for repeating the same phrases or lists of people - to ensure clarity of purpose. That said, if the group of people you list are nominated as 'the bank' I would have expected the drafter to use that word thereafter and not repeat the same list.
When you talk about long lines, I assume you mean there are very long sentences. This is typical of a certain legal style which is possibly more about confusing the layman than ensuring legal clarity. Again, try inserting some punctuation, including full stops and see if this makes things clearer. And where you come across a word which either you are unfamiliar with, or you think may have a special legal meaning (for example 'consideration' in a contract means something of value) then check the word in a legal dictionary. For nineteenth century documents try
Blacks Law Dictionary 1891. There are also several more modern ones on line. Another useful on line resource is
Lawi
