I'm guessing the Langster is targeting a market of city riders who want track bike feel and less the riders who actually ride the track.
That said, it will do fine as a daily rider but here in the northwest, not an ideal bike. I doubt it has fender eyes and might not have room under the fork and rear brake bridge. Two brakes can be quite useful. I'm pretty certain that bike is drilled for a rear brake so you can add it.
If you mean commuter/errand bike, fenders are really nice. A drawback to bikes like yours with track ends (the slotted plates the rear wheel slides into from the rear) is that wheel removal with fenders is a nuisance. Older style roadbikes with forward facing dropouts are far easier, very often come with fender eyes and usually have plenty of room for fenders, making them far better utility bikes. (But do your best to find a bike with a highish bottom bracket. I consider 10-5/8", road to center of bottom bracket spindle the minimum, 10-3/4" better.)
It looks like you are using platform pedals. You will find going up steep hills far more fun if you go to either old-fashioned toeclips and straps or clipless pedals. Going downhill toeclips and straps have a very real safety advantage. Your foot stays on the pedal even if you un-clip. Going fast downhill means pedaling very fast, (A 42-17 gar ratio means 200 RPM at 40 mph.) If your foot comes off the pedal, you are likely to be struck very hard by the pedal in your Achilles which could be a life-long issue. (You are also very likely to crash but the pedal strike will probably be the worse of the two.) If you want to go with toeclips, quote my post or PM me and I'll share what I've done to modify pedals to make pick up on starts far easier. (You have two pedal revolutions to get the pedal. After that, you are going to fast,)
I ride a '83 Trek 4-something set up with drop bars, two excellent brakes and fenders as a year-round commuter, errand, in-town bike. Been doing it 43 years (starting with a Peugeot UO-8 converted to fix gear). That series of fix gears have 80,000 miles on them. Been up and down California's Mt Diablo. Ridden centuries. Rain, snow. You name it.
Minor point - sure you went up a 30 degree grade? 30% I'd believe. (30% is VERY steep.)
Keep riding fixed! It's a way of like!
Ben