I'd put steering both inside and out. I can tell you from experience that you will enjoy both depending on the weather.

Nimble solves the "footwell" problem for the inside helm position by making the forward part of the settee berth removeable. The first pict shows the stbd settee in sleeper mode. You can see that the forward section is removeable.

The second pict pict shows the forward section of the port settee removed and the helm seat in position. The seat pole slides into a recptacle which is built into the storage compartment under the fixed part of the settee.

As for your motor choice, I expect that a HT 9.9 will do well for you. Two years ago I repowered my Arctic and posted my experience/findings on TSBB. If you can't find it in the archives I can email it.