To fit a door closer outside on the pull (hinges visible) side of the door is not a problem. Corrosion resistance like this can only be achieved with a “Wetroom” finish. I’d recommend FIRSTLY EITHER:- a Geze TS4000 body only “Wetroom” door closer with a hold open arm in “Wetroom” finish. OR SECONDLY:- you could fit a guide rail door closer on the inside of the door with a mechanical hold open, then the arm will not stick out and catch on the blinds. For that you’d need the TS3000V body only, the Rail & arm opposite hinge side and the Mechanical hold open device. However, is there any danger of the wind picking the door up and slamming it open? If so, then the FIRST option would be better because that door closer has back check as standard. If you use a guide rail closer in that situation then a gust of wind could break the door closer at 120°.