I agree with whatever you said and me being a person who did game dev in the past but took a break and getting back on track (dont get much time for developing games but atleast have time for helping the community with the experience) , this advice is actually helpful and I will recommend this as well.
For the first point, even If your game doesnt look nice or doesnt have good graphics, put on some pics, screenshots and a good summary of your game, even if it isnt good. Be proud that you made something and it could lead to something bigger and better. And plus putting screenshots and trailers really does make a good impact on your itch.io page
The 3rd point is a really good way to get views and to get people to play your game and get more exposure but as one of the person in this reply section pointed out that game jams r gold for exposures but have certain limits (as in the limits and the boundaries like themes and stuff which the game has to revoke around, what the game can have etc.) They can give you an advantage and a disadvantage. Recommend it for short projects and for fun ofc and for beginners but if you plan to make a really full fletched game, then take some time off and put dedication to your game and then use the posts and basically try to get a good reach on people.
And above all always have fun. The community in itch.io also exists for a reason. Have fun and explore the community