What i also noticed is that you dont really use the letterf
My apologies for not addressing the 2nd part of your original question regarding Polish use of letter f. Letter f is more common in Polish pronunciation than in Polish spelling, due to Polish letter w being sometimes pronounced (or "devoiced") as letter f, even though still spelled as letter w.
For example, Polish w in first-letter position is devoiced as letter f, if the next consonants before the very 1st vowel are c, ch, ci (pronounced as ć, and letter i is pronounced only if spelled before a consonant or in last-letter position), cz, f, h, k, p, s, si (pronounced as ś, and letter i pronounced only before a consonant or last-letter position), sz, and t. Polish rz in first-letter position is also devoiced as sz, if followed in spelling by the same next consonants, before 1st vowel. The original spellings remain unchanged, despite changes in pronunciations. The devoicing rules also apply if the consonant clusters listed above are spelled between vowels.
Polish letter w is also devoiced as letter f, if spelled with the above consonants in vice-versa order, before the very 1st vowel. So letters c, ch, ć, cz, f, h, k, p, s, ś, sz, and t in first-letter positions followed by letters w + 1st vowel in spelling, but pronounced as f + 1st vowel. The devoicing rules also apply if the same first-letter consonants are followed in spelling by wj, wl, wł, wm, wn/wni, wr, and wrz (letter w devoiced as f, and wrz devoiced as fsz) before 1st vowel. Polish rz is also devoiced as sz, if spelled after the above consonants, before 1st vowel. The devoicing rules would also apply if the listed first-letter consonants are followed in spelling by hypothetical but nonexistents rzj, rzl, rzł, rzm, rzn/rzni, and rzr, and rzrz (rz devoiced as sz, and nonexistent rzrz would be hypothetically devoiced as szsz) before 1st vowel. Once again, the original spellings also remain unchanged. And once again, the devoicing rules also apply if the consonant clusters listed above are spelled between vowels.
Consonants in last-letter position are pronounced as voiced consonants only if the very next word in sequence has a voiced consonant pronunciation in first-letter position, and only if there's no spoken hesitation between those words. Voiced consonant pronunciations in first-letter positions are individual or clustered letters b, d, dz, dzi (pronounced as dź, and letter i is pronounced only if spelled before a consonant or in last-letter position), dż, g, rz, w, z, zi (pronounced as ź, and letter i pronounced only before a consonant or last-letter position), and ż, before very 1st vowel. The above voiced consonants are also pronounced as voiced if immediately followed by consonants j, l, ł, m, n/ni, and r, before 1st vowel. Voiceless consonants c, ch, ci, cz, f, h, k, p, s, si, sz, t, in first-letter position are pronounced as respective voiced counterparts dz, voiced ch, dzi, dż, w, voiced h, g, b, z, zi, rz/ż, d, only if voiced consonants (excluding w and rz) are in next-letter position, before 1st vowel. Also pronounced as voiced if the above voiced consonant clusters are immediately followed by consonants j, l, ł, m, n/ni, and r, before 1st vowel. As before, the original spellings remain unchanged.
In some parts of Poland, consonants in last-letter position are also pronounced as voiced consonants if the very next word in sequence begins with a vowel, and also only if there's no spoken hesitation between those words. Also in some parts of Poland, consonants in last-letter position are also pronounced as voiced consonants if the very next word in sequence begins with j, l, ł, m, n/ni, and r, and only if there's no spoken hesitation between those words. As before, the original spellings remain unchanged.
Letter w as preposition (w as preposition means at/in/inside/inside of) is devoiced as letter f, if name of location has a voiceless consonant pronunciation in first-letter position. Same with W- as prefix (W- is prefixed mostly onto infinitives, and also adjectives, adverbs, and nouns derived from infinitives), if name of infinitive etc also has a voiceless consonant pronunciation in first-letter position. As before, the original spellings remain unchanged.