I am sure someone will post soon that can help; perhaps some more information will be helpful though.
/dev/sda1 -- ntfs -- 450MB / 39.45MB free -- hidden, diag
^^^ This must be your recovery partition, to reinstall windows.
/dev/sda2 -- fat32 -- 100MB / 66.94MB free -- boot, esp
^^^ Do you remember if you formatted this boot partition when you installed Manjaro the last time??
/dev/sda3 -- reserved -- 16MB / X -- msftres
^^^ We don't wanna ever format this one of course (Windows).
/dev/sda4 -- ntfs -- 246.28GB / 64.89GB free -- msftdata
^^^ This is where you have Windows install, correct?
/dev/sda4 -- "unallocated" -- 200.00GB / X free -- X
^^^ From your notes, I can tell this is where Manjaro was installed; and you were going to install it here again. Got it.
FYI: This is not typically required, I suggest in the future running Manjaro setup; then select the "manual" partitioning method. You could set it to format the partition at that time, without taking the extra steps of doing it in Gparted.
As you noted, you do not want to format, or delete the /dev/sda2 partition; this would break Windows.
A coupe recommendations for future reference.
You could sometimes run into trouble keeping your data files ("My Documents" and/or "/home/"), on the same partition. If you end up having to do an operating system reinstall (OSRI), you could end up wiping out your data files.
Also: I would like to discourage you from using logical partitions. Using either MS-DOS or GPT, you can have no more than 4 primary partitions. It's happened to me twice, on two different HDD's; but the super-block on my logical partition(s) were corrupted somehow (I don't know how), and only impacted the logical volumes--but I did lose some data.
Point being: Others may disagree, but I'd discourage you from using logical partitions; but in this case, it's difficult not to dual booting with Windows and Manjaro--you can only have 4 primary partitions.
Don't worry about that right now, but something to think about later.
I bring this up, as: Windows requires 3 partitions, minimum (reserved, OS, boot), and it's best to use 3 partitions for Manjaro (root, home, swap); boot partition can be shared.
To use a shared EFI boot partition, this article recommends a 500mb partition; sounds slightly excessive, but.
"Dual booting Windows and Linux using UEFI" (2019)
If you plan on dual-booting with Windows long-term, I suggest getting a second HDD. This will help avoid using logical partitions (if you lose one, you could lose them all); and will help keep your OS files and personal data files on separate partitions.
Windows gives you an option (once installed and logged in), to move your "My Documents" folder to another partition; to get it off of drive C:.
You could get an SSD for fast booting, and put Windows OS (C:), on it; and put Manjaro / (root), and then perhaps the Manjaro Swap partition on it (optional).
Then you could put your data files (My Documents, and /home/), on your regular HDD; that way you're using primary partitions, and all of your OS files and personal files are on separate partitions. Or, you could do the same with 2 HDD's.
The Linux Swap partition is rarely used, only when you run out of DDRAM (memory); you can use a swap file the way Windows does, but that's more complex to setup (I haven't done it, don't need to).
Anyway, I'd love to try and help you more; but I'm the OSRI King!
Linux hasn't forced me to learn troubleshooting the way Windows does; if I run into a big problem I can't fix in 30-60 minutes, I just format over my root and boot partitions (leaving my /home/ untouched, and just assigned to /home/ w/out formatting it), then update and done. lol
That's just me. Let me know if you have any questions though. Thanks.
Sorry, don't mean to overwhelm you; just wanted to help you for the future if you dual-boot long-term.
BTW: What's your system info: desktop/laptop, model# of it, and the LiveCD ISO version you're using (eg: 19.1.5 or?)?