I am well aware of SkyVector limitations but would respectfully disagree - as a real world pilot too - that 9 FP out of 10 would be rejected, that has yet to happen to me and I am flying worldwide…
So to take your objections one by one, (1) one-way airways are shown, (2) minimum safe altitudes are shown as well if you zoom a particular sector, like on a Jeppesen enroule map (the minimum altitude for each airway segments will NOT appear though), (3) SkyVector is, indeed, used by real world pilots, please go to that page to create your account, and, finally, we are talking of creating flight-plans for a simulator, SkyVector is much more than one will ever need to make realistic flight-plans in MSFS or P3D, transfer them to SimBrief (where you can verify it with the latest AIRAC if you have it) and transfer them to MSFS.
In addition to the above NOTAMs and SIGMETs are depicted and updated along with the latest information on airports, and all that… for free!