No, 
PixelPower is not a moderator. Reminder PP, backseat moderating is not encouraged on those forums, please behave.
Avoid not-constructive answers where you are not actually providing support.
Nevertheless, he's right on one point, the people providing answers in the forums do it on their free time, on their own will, on what they want to answer.
Moreover, when sometime a question does not get an answer, it is often because either the solution can be easily found out by using the search feature, looking into the manual, how do I FAQ, C2 Academy playlist, and other existing informations resources, or because the question is not detailed enough.
1. Those manual articles are critical for answers on performances and how to deal with it : performance tips, memory usage. For starters, there are the rules to follow.
Then, as indicated in the best practices you are to test out your project often on your target device, and as such, you can know quickly when you are hitting a peak/limitation in performances depending on the specific device.
When this happens, or you have specific performances question out of the frame of the manual articles, answer your own performance questions with measurements as there is no "fit-all-sizes" answers on that front.
Overall though, layout size is not an issue. The number of instances and the size of the textures within those instances on the other hand can lead to issues.
2. It depends on your usage. Each frame can have its own collision polygon, but if you are willing to have some consistent collisions through an animation, it might be useful to have the polygon consistent over it as well.
The article on image and animation editor states the fact that right-clicking in the image editor window will display a context menu to help having the same polygon over the animation.
3. I tend to regroup all the actions in the same event as well.
Also be aware that instead of a "Every tick" condition, you can choose to have the event (or sub-event) as blank, and it will act the same.
Sub-events can also act as "other condition" in that case.
Have a top level blank or "Every tick" event, and as sub-event, check the value of some variable, or do any other kind of check, that will make logical sense and allow you to keep a good organisation of your events. It will have the advantage to make sure the check happens at this point of the code's execution (especially if they are not triggered conditions)
4 has already been answered.
Here is a capx that does nothing more than what is explained in said tutorial. It is even hard to see what it does since there are close to no pictures to load in that example.
You can, when in need, ask for precisions for specific cases. The more precise the question, the most detailed the answers will be.
But on the other hand, don't expect other to make your project for you either, a lot of newcomers/requests sound like that and are often ignored because of it.
5. This also is greatly dependent on your project. In the absolute, JS error should not happen. If you encounter one, it could be because you use a third-part addon that actually cause the issue, or as BlackHornet mentioned, you made some infinite loop and find yourself into some recursion.
When such an error happens, a dialog appears and do display a message. That actual message explains what the error likely is, and where you could/should fix it in your events.
Checking the browser for errors might also give further clues as to what the issue exactly is, and at last, posting your capx and how to reproduce the issue, allowing to get help from the community is your best bet as well.
On our forums, it is OK to bump a topic after 24 hours, but avoid just bumps for the sake of bumps, your best shot is always to show your researches and attempts to fix an issue in the meantime.
There is no obligation of answers by the community, and it all depends on the availability of people passing by at the moment you post.