Hi bod,
1. It's not hastar but mastar hali.
2. To make a noun sentence negative we use "değil" (isn't). To make a verb sentence negative we use the negative suffix -me, -ma.
A noun sentence is a sentence that hasn't a conjugated verb but has a noun or adjective. Example:
İstanbul çok güzel. > Noun sentence because of 'güzel'.
Ankara pek güzel değil. > Noun sentence because of 'güzel'.
Ali okula gitti. > verb sentence because of gitmek.
Ali okula gitmedi. > verb sentence because of gitmek.

3. Mastal hali is the infinitive but 'gitme', 'incitme', 'okuma', 'yazma', etc. are negative imperatives. Smillarly 'git', 'incit', 'oku', 'yaz', etc. are affirmative imperatives. They are not infinitives.

The infinitives are 'gitmek' (to go) , 'incitmek' (to hurt), 'okumak' (to read) , 'yazmak' (to write), etc. and the negative imperatives are 'gitmemek' (not to go) , 'incitmemek' (not to hurt), 'okumamak' (not to read) , 'yazmamak' (not to write), etc.

Here are some sentences with negative imperatives:

Hayvanları incitmemek önemli.
Kitap okumamak çok büyük bir eksiklik.
Gitmemek ayıp olur.
Önemsiz sorulara kısa cevaplar vermek ve uzun uzun yazmamak gerekir.

Anlıyorum caliptrix. Bod'u küçük şeyler yüzünden üzmek istemediniz. Çok düşÃ¼ncelisiniz. Bod, iyi bir öğrenci öyle değil mi?
(Yabancı arkadaşlara biraz pratik olsun diye Türkçe yazdım.)

Okay, I don't know that much about Turkish, but as far as grammar goes, I can tell you you don't want a verbal noun, you want a participle adjective. The -me suffix doesn't always translate to -ing in English.

For example, if you say, "I like reading", "reading" is a gerund, which is like a nounified verb. "Okulmayı seviyorum," right? It works like a noun, and you can use it as the object of the sentence (or the subject. ex. "Reading makes me happy." "Hurting animals is a bad idea.")

But if you say "These are the hurting animals," you're using it as an adjective (present participle), and the Turkish present participle is made with -en.

Sorry, didn't notice you had two more pages of replies. I guess the question had probably been answered already...