I believe Majestic-san meant ~をしたほうがいいです as ~た方がいいです, i.e., "affirmative + 方がいい", while you used ~ない方がいいです in your answer.
Oh, I see, my bad.
No, you can't use そうでは with 思いません.
Okay, そうは seems to sound sort of awkward to me, as far as pronunciation is concerned.
Sounds very awkward. Haven't you learned a structure for listing actions ~たり…たり (e.g. ~たり…たりしたい or ~たり…たりしない方がいい) yet?
Indeed, I have.
日本語で動画を分かったり、本を分かったりしたいから。
Shall I better use 日本の instead, or add 日本語で before 本, too?
By the way, I've just read about potential verbs in Genki, and I am now on し topic.
If I am to use polite form should I use long form before し?
Okay, I saw in the page bottom note it's said to be used with long forms in the very polite speech style.
It says when we use ~そうです("it looks like"), we are guessing what something is like on the basis of our impressions, or when we lack conclusive evidence. Can I say "That guy seems like a bad person, but [ he is actually a really kind one ] /
[ I think / know he is actually really kind ]" ? Like, when some person has some impression, but I don't think that way?
Also, can I use it with noun? (It's described only about adjectives and verbs). For example, some guy is seemingly student: この人は学生そうです。or 学生そうな人銀行に入りました。? (A person who seems to be a student entered a bank)
「あなた、もしは傲慢でありませんですかね~」
Why is there です after ありません, it shouldn't be after a verb, right? (I heard it an anime)