I haven't gotten married yet and still live with my parents.

I do actually think you're right, however "gotten" seems to be dropping out of usage, I think due to the fact people seem to be using it as slang where only "got" would be grammatically correct, hence why I thought it necessary to add my correction (although I did actually "mark as correct" first of all, it was very difficult for me to judge, so I think yours is fine, honestly, I was just trying to provide a more natural sounding alternative.

TBeing an only child with no cousins, they often encourage me to find a good partner due to the absence of siblings and cousinssuitable partner.

The use of the gerund "being" is often more appropriate for describing a person's circumstances I think.

I can't make up my mind toThe prospect of moveing out of their house andto live by myself becauseseems like a daunting one, as living in Tokyo is really costs a lotexpensive.

I think I understood you want to express indecision, the expression "make up my mind" is more appropriate for single occasions as opposed to an ongoing dilemma. I think perhaps you wanted to express "daunting" meaning fear caused by uncertainty or something which seems too big or difficult to handle.

In addition, I haveMoreover I might need to find another new house soon if I would changeurgently, if I got a new job, or be supposed to live with someonfound a more convenient living arrangement with other people, for example.

I hope it didn't alter the meaning of what you wanted to say, if I did then I'm sorry, I was simply trying to make it sound more like the style of a native speaker.

My uncle is a bitquite a childish and annoyirritating person.

Before adjectives, you could say "a bit of a" or however other expression which I think are more common are "quite a" or "a rather" I think these often convey negative emotions, like contempt.

He always treats me as iflike I'm still a teenager and treats his parents in a rough manner also.

Perfect, I just changed it a little to hopefully make the sentence flow more naturally.

He is however, he is a competent freelance engineer and could afford to go out for a drink every day.

This use of "however" after the word "is" adds more emphasis, and can be used to contrast a previous statement. Also "everyday" is an adjective to describe something, like "everyday events" it was a good effort, however in this instance "every day" fits better.

I've heard from his drinking buddies that he's a really faithfultrustworthy person.

You should add the indefinite article "a" before a phrase describing a person or thing, while yes, it would also be correct to say "He's really trustworthy" (I think this word sounds more fitting) by itself, because this phrase modifies the word person, you should insert the indefinite article "a".

Even though my grandfather is ninety-two years old, his conscious is still clearmind still functions normally.

It was understandable, however difficult for me to determine the exact, precise meaning, so I hope I didn't alter it.

It seems that he hadHe appears to have run his own business.

"appears to" indicates something you are aware of but would have difficulty understanding the whole process of.

I'm not familiar with might not know much about his career, but I do know how honest and kind he is.

This structure adds more emphasis. There are different nuances with different verbs, but this structure "might not....but..." makes it clear that whatever statement comes after "but" is noteworthy, and deserves recognition in most cases I think.

I can't make up my mindbring myself to move out of their house and live by myself because living in Tokyo really costs a lot.

In addition, I have to find another house soon if I would change job or be supposed to live with someone.

I'm not actually sure what this sentence means. Could you explain and I'll offer some suggestions?

My uncle is a bit childish and an annoying person.

However, he is a competent freelance engineer and couldan afford to go out for a drink everyday.

present tense.

If you're stating an opinion about how your uncle could improve in some regard, you could say "he could afford to go out for a drink everyday."

Even though my grandfather is ninety-two years old, his consciousgnition is still clesharp.

Usually we would say 'his mind is still clear/sharp,' but I wanted to provide a word from the register you seem to be going for.

In addition, I have to find another house soon if I would change job or be supposed to live with someone.

I'm not entirely sure what you're trying to say in this sentence? I can't really correct it because any of my corrections might change your intended meaning. If you see this and feel like clarifying what you're saying I would love to help you out with this part!!

My uncle is a bit of a childish and annoying person.

However, he is a competent freelance engineer and couldan afford to go out for a drink everyday.

I've heard from his drinking buddies that he's a really faithful person.

Even though my grandfather is ninety-two years old, his consciousence is still clear.

The words "conscious" and "conscience" sound very similar but are actually two different words! "Conscious" is a describing word that means someone is awake or aware of their surroundings. Conscience is a noun (person, place, or thing). :)