My Try: Sevdiklerin(iz)e olan etkisini dikkate almalısın(ız).

Well you go suffix by suffix and you get the meaning. 

Gerçek- true, real.

-leş- to become (nouns to verbs) Türkleşmek- to become Turk

-tir- causative- to cause to. Easiest example is the verb to kill: Öldürmek- which literally translates to ´To cause to die´.

-il- reflexive- Sevmek- to love, Sevilmek- to be loved. 

-miş- something you personally did not witness, you just heard it. Or, heard past tense. (Duyulan geçmiş zaman)

So your exact translation: Gerçekleştirilmiş- İt was caused to become real (But you did not witness it). 

Shouldn´t it be Hollandalıdan? As in Hollandalıyım? Because the ´lı´ shows the belonging to a specific place.

Let´s say a German person makes fun of Dutch people, just in a fun or joking way. Then someone else notices the German person does the same things that he was joking about Dutch people. How would this sound in Turkish, to jokingly call the German of acting hypocritical: 

Hollandalısınız.

Hollandalıdan farklı yok.

What is this, gerund, participle?

If someone says another person is a "biraz rahatsız" person.

What would that mean? I think that would likely mean they think that person is troubled.

What is mean? Bilen (bilmek).