I doubt いくらか/いくつか, いくらも/いくつも いくらでも/いくつでも should be called "interrogatives." They don't make a interrogative sentence by themselves. いくらか = "some (uncountable)", いくつか = "a few (countable)", いくらでも "no matter how many/much (countable/uncountable)", いくつでも "no matter how many (countable)"
いくらも is slightly uncommon. I think it's mostly used together with ない especially in literature, as in
[we] don't have much left
On the other hand いくつも is very common, = "a lot of"
いくら is an interrogative. It can either mean "how many" or "how much is the price", but I think it increasingly means only the latter nowadays.
How much is this [slice of] mackerel?
On the other hand いくつ and Chinese-originated 何個(nanko) is taking the place as an interrogative for number of items.
How many do you need?
The notable usage of いくつ (not 何個) is asking the age of a person:
Forgive my rudeness [if you don't mind me asking], how old are you?
どのくらい is also an interrogative to ask "to what extent" "to what degree" or "how intense." It's very versatile.
How long should I grill this piece of meat?
How much time has passed since then
It can even mean "how much":
How much of paint do we need for [covering] the wall?