It really depends what look you're after. Classically the rule of thumb is the skirting should be 1/17th the height of the ceiling. This is just a pleasant ratio from a visual perspective. I'm not keen on stubby low skirting because it often looks like the 'cheap' option (as if the architrave was used for skirting). It does depend on the style of house to some extent but there's not many instances low skirting really adds anything to a space. Do consider things like: the abuse skirting takes from vacuum cleaners, what height you have/want power outlets to be. What style of architrave you want (a nice thick architrave helps 'frame' doors and tricks the eye into thinking the doorway is larger than it is - I've attached a before and after showing how this works on window casing but it's the same principle) and other wood work nearby - how will it all look together? Also upkeep - complex profiles mean more dusting! I would also recommend buying pre-primed skirting where possible - it's so much easier when you only need to do one coat of paint!

Most manufacturers have a durable matt. Personally I get the local decorating centre to mix paints from other manufacturers as my painter doesn't like using Farrow and Ball paints. This way I can get the colour I want plus I am a firm believer in keeping your trades happy.

I have just done mine in dulux semi gloss woodcare. It has a mostly matt appearance buy does shine in direct light. Also makes them easier to clean

If you didn't have the waterfall worktop and it was a decor panel (to match the door colour) you'd have skirting so I'd do the same with the worktop. To me I think it would look odd without skirting especially as it then goes into the knock through, then would you not have any skirting in the rest of the room, which I think would look unfinished. Like a said in an earlier post, the skirting is to cover the gap between the floor and wall finish, if the plaster carries on down to the floor, there's more chance of getting water damage.