No. Instead, (depending on what type of practice we're talking about here) 練習は何時間がかかりますか。
or
練習はどのくらい時間がかかりますか。
etc.

時間がかかる here means "time is spent," so the question is literally "As for practice, how much time is spent?"

Thanks again for the help masaegu :)

Now for today's questions, if you don't mind.

1. http://i.imgur.com/COPms.jpg
Do you know what she is referring to by キャプチュート? As for キトクラッチ, could it be "Kido clutch"?

2. http://i.imgur.com/OfZjW.jpg
a/ Does 「ン」ってついた mean "ended with ン?"
b/ What does the author mean by 多分「民明書房」あたりには載っている? It looks to me like "probably can be found in Minmei Shobou", but I'm not really sure.

3. The first sentence looks obscure to me. Can you tell me what it means?

4. http://i.imgur.com/3CCOv.jpg
Does まさかとは思うが… mean "I'm wondering, but..."?

5.a/ Does 週マガ mean "weekly magazine"?
b/ The phrase 読みきり出張致します is bugging me. Does it mean that a side story will be published?

I do not mind but I want you to know that I neither read manga nor watch pro-wrestling, so I had to google a lot to answer them.

Both appear to be the names of pro-wrestling attacks. I think the first one is
"Captured" but I cannot confirm it anywhere. The second one is Kido Clutch, which was invented by a Japanese wrestler named Kido.

a. No. It means "There is a ン in it."
b. That is what it means. BUT 民明書房 is an imaginary publishing company that seems to be used a lot in manga.

別マガ　＝　別冊少年マガジン
Bessatsu Shōnen Magazine - Wikipedia, the free encyclopedia

I am only guessing. I know NOTHING about manga. I guess the first phrase means "Both 別マガ and the 単行本 from the 別マガ hit the bookstores on the 9th of each month."

Not really. Your TL does not carry the connotation of まさか.
"I don't think it is the case, but (aren't you thinking that ~~~?)"

a. No. "The Weekly Shounen Magazine", not any weekly magazine.
b. It means that a special complete short story of 『一路平安！』 will appear in the 週マガ44号.

「まさえぐさんは、どうしてそんなに英語がお上手なん ですか？」
or
「どうしてまさえぐさんは、そんなに英語がお上手なん ですか？」
would be more natural.

う～ん・・・どうしてかな・・・？でもhitotszさんも、� �　英語と韓国語が上手でしょう？(^_^)

You want to say 'Do you have any Korean friends?'

「韓国人の友達はいますか？」

I'd say 「普段（ふだん）、どのくらい練習するんですか？」「 普段、どれくらい練習するんですか？/して（い）るんですか？」「いつも、どのくらい練習し て（い）るんですか？」or「毎日(daily)、何時間くらい練 習するんですか/しているんですか？」etc...

If you use 時間がかかる, it sounds as though the person asking the question:

1. cannot wait till the other person is done with the practice. or
2. knows for a fact that the other person does not like to practice whatever s/he practices.

Sumippi gave natural-sounding sentences above.
_____

If you want to use a related word to かかる, use かける and it will no longer sound like someone is not really willing to practice because かける is a transitive verb and it sounds like someone is actually willing to take the time to　practice something.

「練習にどれくらいの時間をかけますか。」
「練習に何時間くらいかけますか。」

Yes. Thank you. What would be the difference between いますか and いるんですか？

Thank you. What is the difference between 上手なんですか and 上手なんですか？

I feel like this is exactly the level I need to be practicing at. As I said before, even light novels aren't written this way. Do you have any ideas where I could find more stuff written like this?

To explain some of my comments:
結果、わたしは本業に支障が出ない範囲でという条件で 寺子屋に通いはじめる。

I chose, "Therefore, I began attending the temple school on the condition that it not interfere with my primary duty."

Given the chance to say it again, instead of calling で a connective, I'd've said, "She prefers adjunct clauses to separate sentences."

支障が出ない, "hindrances do not appear," even though it has the verb 出る, is the kind of place I meant when I said she uses nouns where I would expect verbs. She could have used 差し支える. So the *number* of verbs doesn't change, but how they are used does.

And yes, small as they are, this is still more clauses than I'm used to.

Similar things happen in English, compare "More than once I've awoken to the realization that I have made a mistake in translation" to "Sometimes I wake up and realize I made a mistake in translation."

Wake to the realization > wake up and realize.

More nouns, less verbs (or at the least simpler verbs), adjunct clauses instead of separate sentences. It's a very different way of writing in either language.