How do I customize Adobe Acrobat Standard DC or Adobe Acrobat Pro DC to do what I'd like? Actually this a multiple-question inquiry.

Question

Note, I was unable to find a "How TO", Tutorial, or FAQ relevant to the following questions.
For instance, how do I easily append to an existing PDF with minimum clicks (which I could do with an earlier version of Acrobat Standard)?
I'm using a 30-day trial of Adobe Acrobat Pro DC to scan documents and in certain situations, append to existing PDFs.
I'd prefer to trial the Adobe Acrobat Standard vs. Pro DC because that's what I intend to purchase.  I'd prefer to not get accustomed to Pro if Standard is very different.
1.  After selecting Edit > Preferences and specifying certain defaults, most take effect as suspected but some do not, like the one's I'm going to elaborate on below.  Why?
2. Alternatively, is there a Tool or a way to create a local customized Profile and default to that Profile to avoid having to repeat the following steps?
   This should not be confused with the online Profile (or Communities Profile) whereby one states one's Name etc.
File
> Create
   > PDF from scanner
     > Custom scan
       > Color Mode: Black and White
       > Append to existing file
         > Browse
           > Select file
             > Scan
This is a cumbersome task to repeat each time I'm ready to scan.  Using an earlier version of Acrobat Standard, I'd simply double-click the PDF I wished to append to,
Acrobat would default to the appropriate scanner, and know that I wished to append to an existing file without me having to select that option.  Presently it doesn't appear to be that easy/simple.
Perhaps it is (or can be with guidance).  Please assist.
3. Please find attached the following snapshots/images... CORRECTION, IF ADOBE SUPPORT CONTACTS ME ABOUT THIS, I'LL GLADLY FORWARD SCREENSHOTS.
   Meaning, there does not appear to be a way to include screenshots on Forums.
3a See Error.  Is there a way to get a more accurate description of the error (i.e., turn on debugging etc.)?
3b When Creating a PDF, the prompts still seen after clicking "Configure Presets" and changing Color Mode from AutoDetect to Black and White.  Why?
3c Custom Scan Input, where I changed Color Mode from AutoDetect to Black and White and why I must also tell Acrobat to append AND to browse to a pre-defined default location?
4. Must I be "Logged in" to use the product?  The first time launching it, I was prompted to login using the credentials used to create the account and download the product.  Now when using the product it appears to be automatically "Logged in" or online.  I would prefer to use it in an "offline mode" if there is such a thing.
5. Once the product is purchased, what are my support options?  Can questions be answered or issues resolved with a phone call or are they limited to the Acrobat Forum(s) and/or Adobe Communities?  Even after clicking "Ready to contact us?  Start here." I'm only given the Forum option (over and over) vs. Chat vs. Email Support etc.
If I've posted these inquiries to the wrong Forum or Discussion, if prudent, please collectively relocate them.  Regardless, please advise.  Thanks!

Answer 1

uninstall all acrobat/reader versions and retry installing.
or check your log files for more specific help, Troubleshoot install issues with log files | CS5, CS5.5, CS6