Language / How to say 'more' in various contexts [9]

The way it was explained to me, więcej can be used for 'more quantity' and 'bardziej' as 'more size', but the use seems inconsistent to me in real life. If I'm getting almonds at a kiosk, and the seller scoops a bit, but I want a more, do i use więcej? Someone pours me some water but i want more? Someone cuts me a piece of cake but I want more? If i want to say I now make more money? If I want to say that want more optimism from you? People in France are more elegant? The ice here is more slippery? I am more sick?

In real life I keep finding myself being corrected, not understanding the logic.

Language / In a restaurant, how do I say I want my food to go? For takeout? [7]

The words "to go" and "take out" are so freaking common that there's no way to do an internet search for this in the right context. Not to mention "polish" (as in nail polish).

Can I say, "do wyjąć"?

Language / rules for genetive declension of female nouns ending in 'a' [8]

I'll preface this by saying that it's been difficult gathering the rules of declension. Most sources like books, websites, and course materials give an incomplete abbreviated version. If anyone has a source with a complete set of *every rule* for declension, please let me know. I know a lot of them are special cases, but it would be good to have the non-special case rules.

Here's what I've gathered thus far:
SINGULAR: if the second to last letter is...
k, g, j, or l then the declension ends in an i:
dziewczynka -> dwiewczynki
droga -> drogi
kolacja -> kolacji
koszula -> koszuli
If the second to last letter is 'i', just drop the 'a' for domestic words...
kawiarnia -> kawiarni
...and add an extra 'i' for foreign-derived words:
harmonia -> harmonii
For all other second to last letters, use a 'y':
eg, koperta -> koperty

PLURAL:
If the second to last letter is a 'k' then the ending becomes 'ek':
dziewczynka -> dziewczynek
This one I'm vague on, but the examples I've looked at all seem to pan out:
if the word ends in 'cza' then it ends in a 'y' (and equal to singular genetive):
pomarańcza -> pomarańczy
In foreign-derived words where the second to last letter is an 'i', you add an extra 'i' (and equal to singular genetive):
harmonia -> harmonii
if the word ends in 'oga', you make it 'óg':
droga -> dróg
In all other cases, you omit the last letter:
kawiarnia -> kawiarni
koszula -> koszul

Does this sound complete? Anything I'm missing? Thanks in advance!

I'll add that I'm doing this because I'm writing a program to help me with Polish. As I'm reading srories, lessons, news, etc, I can highlight a any word and the program would give me the meaning of the word, which declension is being used, and why. Don't know if it will be useful to anyone else after I'm further along but for now it's an interesting hobby :)

Information is so spread out about Polish. I just wanted other people's input. For example, the words ending in 'cza' becoming 'czy' is one rule I don't see written anywhere.