The pronunciation of the letter E depends on the accent. Brazil is a very large country so different regions have different accents. In the south, for exemple, people usually say "hojE", "quentE", and not "hoji", "quenti". There's this sentence that sometimes we use to make fun (not in an offensive way) of southerns "Leite quente dá dor de dente" (hot milk causes toothache). It's kind of funny because they will pronounce every E as E, not as I. Besides, even when people say E as I, there are different ways to pronounce it. You will notice the difference when someone from Nordeste and someone from Minas Gerais say "gente". The first person will say "genti" ("ti" as in Spanish), and the second one will say "gentchi" (as "chi" in Spanish). Some dictionaries have the phonetic indication of how to pronounce a word, but I never noticed if they show these accent differences. Regarding the letter A, it's pronunciation won't change with the accent (as far as I know).

Na verdade, a palavra "ele" é pronunciada "eli" também. Nós não falamos "ÊLE".

What you were told about the letter "a" is very incomplete or even wrong. The letter "a" has got two sounds as oral vowels, one as a nasal vowel and another as a nasal diphthong. Oral Vowels a -> /â/ or /á/ In some regions of Brazil, the distinction of these two sounds is not so strong as in other regions or in Portugal, but there is always a difference. Do not believe in some grammars that speak as if there were only one sound. (We say in Portuguese that the first is closed and the second is open, but I am not sure about the English terminology...) casa -> /cásâ/, ana ->/ánâ/ banana-> /bánánâ/ semana -> /sêmánâ/ "ana", "banana", "semana" has got no nasal vowels because of the way you say the syllables: "a-na"; "ba-na-na"; "se-ma-na". The nasal vowel is pronounced when the tilde is present "ã" or when "a" is followed by "n" or "m" IN THE SAME SYLLABLE. amanhã-> /ámânhã/, maçã->/máçã/, cantar->/cãtár/ When "m" or "n" is at the end of the words "a" yields a nasal diphthong as "ão" without stressing the syllable. cantaram=they song -> /cãtárãw/ cantarão=they will sing ->/cãtárãw/ The only difference about the pronunciations of these words is in the stressed syllable "canTAram" but "cantaRÃO"

Olá :) A complete dictionary will give you a general pronunciation (a simple one probably won't) but like it was said before, the difference between the pronunciation of the word 'ele' and 'eli', for example, is related to regional accent, it's not about exceptions on pronunciation rules. I would say 'eli' but I know a lot of people who say 'ele' in my own state, they just were born in another city. Punctuated words, such as 'maçã', 'irmão', etc. are easier to know how to pronounce them for sure once you learn their pronunciation because they won't variate, the others we learn by heart

Usually, the sound of "e" in "ele" is like the sound in "nome". I said "usually" because there are different accents even in the same region. But more often people said "eli" instead of "ele". Not sure but I guess that the best way to get those pronunciations working is listen native people speaking and try to memorize and repeat. The following url is a video about pronouns at an instant with a clear pronunciation of the word ele: https://youtu.be/xoXS65mBQOs?t=82