I'm the wrong person to ask about this one. I actually never turn my computers off or put them into sleep mode; I just let them run 24/7. (Admittedly, I'm playing around with my own mail and web servers, so I've got a reason to keep at least one of my machines up all the time.) My uptime is limited mainly by how long I can go between power outages that I can't bridge with my UPSs; I normally get about a year to a year and a half uptime on my Linux boxes.
Ah, you mean a GUI file explorer? The two major GUI environments today are Gnome and KDE, and I think both of them have some form of session management. I tend to favor using the command line to manage files myself, so I can't really speak for either of them...
You'll want to choose one of the user-friendlier distributions, they have GUIs to support service management. Ubuntu would probably be a good choice, I think. (Again, as I mostly manage services via the command line, I probably shouldn't comment here.)
The Windows Registry is almost a unique feature in the history of operating systems; I don't think any OS before or since has gone to such lengths to integrate user-application parameters directly into itself. Certainly, you don't have to reboot Linux or OSX every time you install or remove a piece of software.
Ah, that depends entirely on the file system being used. The old "FAT" system, originally used in MSDOS and older versions of Windows, is fully supported under Linux (and practically every other OS in the entire world, it seems). NTFS, the more recent file system used by Windows, is trickier -- there are drivers to read and write it, but because it is heavily patented by Microsoft, these drivers aren't 100% reliable (as they can only be built by reverse-engineering NTFS). I haven't tried playing with NTFS under Linux recently; it seems that "NTFS-3G" does a good job, but I'm not sure I'd want to trust my data to it.
When I was dual-booting Linux and Windows, I just went ahead and used old-fashioned FAT partitions to share data between the two OSs. They may be less efficient than NTFS, but they still work just fine.
Ah, well, it's not so much that a user can read the file, as it is that a programmer can get the technical details on the file format. The OpenDocument Format (.odt, etc.) is an open standard, anyone can create a parser to read those documents. (And I don't personally think they are quite as unreadable as Word docs.) Word, of course, uses a closed proprietary format, and only by careful reverse engineering has it become possible for non-Microsoft products to read .doc files. (And, of course, this is a big reason why Microsoft always comes up with new, incompatible changes to their .doc files with every release, to try and keep ahead of the reverse-engineering folks...)
I've gotta admit, I understand your feeling. Heck, I got my BS at Case Western Reserve University, the alma mater of Don Knuth, who created TeX; even there, where you could find lots of people to teach you how to use it, I just couldn't really get into it.
Actually, icon-editing was the one reason I finally broke down and worked my way through the intricacies of Gimp. It is a massive, complex image editor, but it really can do just about anything you want, if you put enough time and energy into it.
I was going to dual-boot Ubuntu and Windows when I first ventured into Linux OS's. After installing Ubuntu from a CD and finding it did everything better and faster than a Windows machine, I couldn't justify buying Windows.
Talking about Office, LibreOffice worked fine in opening/editing newly created .xlsx spreadsheets. I now can't see myself using anything but Debian based OS's in the future. Edit:- I very often but my Ubuntu system to "Sleep". It takes but a few seconds to wake back up after pressing Esc