If the post/thread you make contains the terms of a quality, constructive and informative post, then you have no reason for Merit Source to skip your post with Merit.
It's not like that merit source will always notice your post as there are hundreds of threads being created daily and it's hard to have an eye on all of them which is why we have many merit sources across across different boards but if you think your topic is good and didn't have merit you can always report them to the thread you have mentioned above.But there are merit distribution from members as well so you can see if you post is really good and helpful you can merits on them to rank up.
I appreciate your efforts for creating a table explaining the merit system but you can simply quote the original author in these cases like we have on the first page and it can be avoided so it's advice to you on this matter as you are not explaining something else so you can see that
The welcome message I feel should be too priority on new implementations to the forum, and the way I see it, would not need much tweaking of the current system, just a pop up for brand-new members.
A welcome message would really be helpful and directing them towards some threads explaining the forum rules and little bit of forum functionality tutorial will also be helpful but that would go into too much demands seeing that we are not seeing simple updations also but if implemented can help newbies a lot if they intend to learn it.