You could well be right, standby does play havoc for many applications, especially applications like monitoring tools, or anything that requires constant media access of some kind, in this case your HDD.
If it's a software issue, you can disable one application at a time by going to
Start, run and type in
msconfig. From the
startup tab, untick one reboot and test. Keep doing this one program at a time until your problem dissapears and you will know if it's an application issue. Then you can decide if you want to use an alternative application or use hybernation instead.
As for the rest, the page file is personal preference. IMHO, 3070 maybe a little too big, maybe 2048. Classic mode does improve system performance in both memory and
CPU. Disk indexing, good (until it comes to searching for files).
I've heard people saying that disks should last forever. but in reality, I've only ever seen one last more than 6-7 years, if looked after. Your PC should have a few years yet, but you will find it more and more difficult to get parts as time goes by.