This is very similar to a detail I am using on a house I am designing. In this house the screen behind the woodburner is a pre-coated steel corrugate. The manufacturers are happy with the temperatures the paint will be exposed to in this situation. Talk to the suppliers of mini-orb to confirm it for your situation. To function as a heat shield the steel needs to have sufficient ventilation space behind it, so needs to be fixed on heat resistant spacers and have sufficient openings top and bottom of the screen to allow the air to flow freely. This can be achievable with sufficient perforations or with clear openings. You will need lining such as plasterboard behind the screen. The detailing of the edges for the screen will affect how the screen works with your design, so think that through.

Friends have a similar cooker (not sure of brand) where the stove is gas but oven can be either gas or electricity run. It too is terrible and seems to cut out during the cooking period or if used with the stove top running. We have recently put in a 900mm westinghouse cooker WFE916SA and it seems fine so far (roast, cakes, muffins etc.) It has gas stove top and electrical only oven.

the reason i love my new induction cooktop is the timer!! put a pot on the stove, set the timer then wander away knowing that the timer will save the saucepan from destruction...don't know about the cost of running the induction, only used for minutes every day so no appreciable cost issues..Love the new down draft exhaust fans and would happily pay extra for one in an open plan kitchen area if you expect to use it while cooking and trying to talk at the same time...it can't easily be added later so i suggest you economise elsewhere...good luck with your new home

In terms of the mantle - it may have been something more fancy previously. We have 3 fireplaces in our little 2x1 - including the one with the stove. Here is a photo of one of them - although it looks like the timber mantle and surrounds have been screwed on at a later date to suit the house rather than being original.