I saw your quesion: "It cuts a few days off the longer shipping route" and was wondering why this one doesn't need "from" then? CUT OFF = remove, subtract, etc. If I take a shortcut, it will cut 2 miles off my trip. CUT OFF FROM = separate from. I'm going to cut myself off from social media.

I wouldn’t take the word “from” away from the 1st sentence otherwise it wouldn’t make sense. For number 2 you can use either way. They would both be correct. I would suggest you use the first one

In the second part of your question, the two different introductory phrases, "aside from the fact" and "regardless of the fact" are both possible, but they mean different things. Aside means that we are consciously disregarding the fact. As a matter of business or logic or whatever our interests are, we have decided to set that matter aside, to ignore it. Regardless means that we don't even care that they are good at X. If it were, say, a discussion about a business deal, "regardless of..." would mean that we will move forward whether they are good at X or not. In this second example, we are not exactly ignoring the matter. Rather, we have addressed the matter and decided that it was not relevant. Perhaps this will further clarify the difference. With "aside", the sentence is hypothetical. We set aside the issue so that we can discuss matters without regard to that fact. With "regardless" we have addressed the issue, as I said above. It is no longer hypothetical. Thus, both are correct and make sense, but they have slightly different meanings.

1. Yes, you can say it that way. I assume that what you mean by this is that you remove comforts from your life, making your life more austere. 2. They are similar. My advice to you would be to avoid the words "regardless" and "irregardless". Those words are overused and a bit confusing. People can't seem to agree what those words actually mean. Use better words instead: aside from the fact other than the fact besides the fact in spite of the fact which have various shades of meanings. Look up synonyms for "besides" in a thesaurus.