Roon Server is designed to be always running, making it’s service available at all times. Background tasks will run from time to time (metadata updates, music files analysis). Such tasks shouldn’t run forever so Roon Server might use all available resources to finish such tasks as quick as possible – it’s only a two core CPU so there is not much chance to save resources to keep the services available during this time (you might not be able to use Roon during this time).
Laptops like the one you refer to are designed to preserve as much electrical power as possible. They may fall into power-save states (including standby) if not actively used by a user for some time – causing trouble for server software becoming unstable or unavailable, over the network at least, until a user logs-in or uses the machine actively (moving the mouse-pointer for example). They are often designed to reduce the maximum processor speed under prolonged periods of high CPU load so the power-consumption doesn’t go over a specific design limit.
IMO laptops aren’t the best platform to run server software on it.
If you choose DSP operations that set your CPU under high load (for e.g.: DSD up/down sampling and/or complex convolution filters) but you can also stress your Core with multiple streams (to different zones or multichannel playback) that use less demanding DSP operations like volume adjustments, parametric EQ, cross-feed, …
There is not only Roon but also the OS (Windows 10 Home 64), user data and possibly other software you may have installed on that machine. I don’t know how much this is already taking up – it’s your machine so just look it up. OS updates may also need additional space and in particular the big Windows 10 updates (upgrades?) may need a lot of space (downloading the new version, installing the new version in parallel to the running one AFAIK).
Roon needs double the space of it’s database while taking or restoring backups AFAIK.
What guidance do you need? You already know that it is pretty comparable to i3/Ivy Bridge (Recommended Minimum Hardware). If you think/need/want more power, use a more potent CPU. This may also depend on what other software is running on your Roon Server laptop and the size of your library – planned for the future not just what you already have unless you do not want to add new music in the future. Read also: My experiences with Rock and a 500k+ tracks library