I recommend using polite forms.
から and そのため sounds stiff. Instead, I would use ので and (勉強する)のに, respectively.
In casual conversations, sentence ending particles are almost always necessary to make it sound natural, and I think it's one of the hardest things to grasp for non-native learners to use those particles appropriately.I was wondering what form I should use, but then I noticed many comments were using plain form so I followed suit. Though If in doubt I suppose it would have been better for me to use polite anyhow.
Are there any specific rules or anything good to know regarding what forms to use when it comes to places such as comments on Youtube and simillar sites?
No rules, just, as Toritoribe-san says, a recommendation. Start with the polite, and progress to casual if the atmosphere allows it, and if you are comfortable with it. Because depending on the situation, casual can come across as rude. This is true for real life in Japan. Polite should be the default, and then one can progress to casual as the situation allows. This tends to be the opposite of how we think in the US, where casual is the default and formal is seen as somehow something only exercised on rare occasions.
Of course, in the raw and unrefined world of Twitter and YouTube, you find all sorts of crude and impolite comments. Anonymity allows everyone to be as rude as they wish to be, so no need to be overly sensitive about how you post there. But as a general rule, "polite" is the default setting in Japan.
In casual conversations, sentence ending particles are almost always necessary to make it sound natural, and I think it's one of the hardest things to grasp for non-native learners to use those particles appropriately.
Also, your wordings are more suitable for polite forms
Words like そのため, このチャネル, とても, 役に立つ or 本当に are proper, therefore could sound stiff in casual conversations. These are more likely written-words-like.Sorry, if you don't mind, could you elaborate on what you mean by this?
Right, it's roughly destination vs. direction.I see that へ is now に. I read that they were interchangable when going somewhere. I originally wrote に but didn't want to repeat に and wondered what would happen if へ was there instead. This page seems to suggest a small nuance, where each makes the reader think of different reasons for going to the destination. Did you change it based on this kind of nuance?
Yes for the omission of を.I also see that there is no を for 買う. I assume that it is casually dropped, and that the rest is a more natural/expressive way of saying it (が places emphasis on the fact I'm looking forward to buying goods?)
Words like そのため, このチャネル, とても, 役に立つ or 本当に are proper, therefore could sound stiff in casual conversations. These are more likely written-words-like.
Right, it's roughly destination vs. direction.
Yes for the omission of を.
楽しみ is the shortened version of 楽しみだ/です, so が is used to indicate the object. On the other hand, your original one 楽しみにしている takes を and が as the object and subject marker, respectively. Thus, 買うのを楽しみ。and 買うのが楽しみにしている。 are both ungrammatical.
Yes.Would を買うのを本当に楽しみにしています be fine then in the right settings?
楽しみにしている is mostly used to convey directly to the listener(s)/reader(s) that the speaker/writer is looking forward to something, so there's no problem to say, for instance, 9月に日本に行くから、会うの楽しみにしてる or 今度日本に行くから、お土産楽しみにしててね to your Japanese friend. In your case, it's closer to monologue, so just 楽しみ is more natural.