Basic questions about DISM

My wife's laptop has a corruption that sfc /scannow could not fix so I am going to try DISM. But first I have some basic questions. (And please forgive any incorrect terminology in the questions.)

Last Sept I used the MCT to build a USB flash memory with Win10 AU. I read in some Tenforums tutorial (which I can no longer find) that the ESD file on the device cannot be used with DISM. But DISM has a source:esd option. Doesn't that work? And even if it does, is it preferable to use an ISO with a .wim file as source?

Whether I do an ISO or USB options, should I download again and let the MCT include the latest fixes?

Assuming I create a medium with the latest fixes, what effect does the DISM "limitaccess" option have? Would it have any need to download anything? Or am I misunderstanding what "limitaccess" does?

Same question if I use my USB from last Sept. Would DISM have to get a lot of updated files in order to fix the corruption?

Update:
I obviously don't know what I'm talking about. Last evening I downloaded the Win10 1607 ISO and it had an Install.esd rather than an install.wim file.

I'm going to forge ahead using the install.esd, but just I'm curious now. How so I get the install.wim file?

LimitAccess prevents DISM from accessing the Microsoft web pages (or other Internet resources) during the search for repair/replacement files. If it works when you don't include LimitAccess, that means it was able to find the files it needs online even if it can't find them on your PC. FYI, the proper syntax for ESD is a little different from that for WIM in the /source attribute, namely:

DISM ... /source:ESD:R:\sources\install.esd:1

Of course, you'll need to replace the italic text above (R:\sources\install.) with the correct path and filename for the ESD file to which you'd like to point.

HTH,
--Ed--

PS: You may find these two blog posts of mine interesting in this connection
Simple Trick Fixes DISM /source syntax issues - The Network Hub
Another Worthwhile DISM Source "Trick" - The Network Hub​

If the source is neither WIM nor ESD, as with my second trick, you don't have to include the WIM: or ESD: at the head of the attribute value, nor point to a segment within the file (that's what the :1, :2, and so forth means at the end, and directs the search to the proper segment in a .wim file that includes x86 and x64 segments, as is often the case). Thanks for asking: you didn't misunderstand. I just probably failed to provide all of the information you needed. Keep asking questions: that's how you learn!
Best wishes,
--Ed--

DISM is big and hairy, with many, many command line options. The TechNet DISM Reference is a good all-around overview (but out of date, alas). I just keep using Google and searching my way into what I need to learn to do, and watching here and other Windows sites for usable nuggets of information.
HTH,
--Ed--