Albeit, they were speeding, however if this "Scares the hell" out of you, then perhaps it would be wise too re-evaluate your mode of transportation.
Clearly you shouldn't be on the road if that scares you. Being scared whilst driving or even whilst riding a childs toy, is to be considered extremely dangerous and this is substantial proof that you cannot use the road under certain circumstances. Henceforth you should not be allowed on the road.
As for the remark about "overtaking" the bus, that is not illegal in any form whatsoever. If you want to let the bus out you can, granted it's probably safer to give way to the bus but not at all mandatory. It would seem you have no idea about proper road usage and it also looks like you are making up your own little laws, thus rendering your belonging on the road even more questionable..
My BMW (dashcam car) was not being moronic and was within the limit (not using 50mph as as target)! I reckon the whole 5 mins of video would have added no useful data other than the second dangerous overtake that occurred. The gap was there because I saw the idiot overtaking another car behind me and I thought "let's not have an accident here" so I let him in! I have 340bhp under my right foot and could've closed that gap in an instant.
A little bit of an ass ole my biker if you dont mind me saying, Your speed needs to keep to the limit, Then you open that guys car door to open his petrol cap, Yeah i know you think you were helping but this is not cozytown this is the UK and people are very particular about their property, Advice stop doing it
Dismissed for time-wasting.