When Clicking on ask Ubuntu I get a different view than when I click on Questions, some questions doesn't appear under Questions! What is the difference between these 2 views? Pressing Ask ubuntu: Pressing Questions gives a different layout, but the 1. question about the bomb emblem is missing!
Other than the layout change, the difference is the default filter/sort.
If you click on the logo of Ask Ubuntu, it will open the homepage which shows, by default, the questions by whichever was last active (adding an answer, editing an answer/question, closing a question, etc. can cause a question to become active and bump it to the top).
On the other hand, if you click on questions, by default, the questions are sorted by "newest". Which means, whichever question was last asked, it will show at the top, disregarding all other activities.
The current selected filter can be seen on the right side, directly above the first question in any of the two page. Featured and active are the only two common filter between the two, the rest is unique to each of the pages.
Tip: Clicking on the "modified/asked/answered x mins/hours ago" gray text in any of the 2 pages, while having the "active" filter selected, will open that question and anchor it directly on that last activity.
For example, if you click "answered 2 mins ago", it will open the question and the page will be anchored directly on that answer.