There are a number of issues with small saws, not just how much room there is underneath the blade guides.
You do need the right blade for the job. The BS is just a driving force, it's the blade that does the cutting, of course.
Marcros is right about the number of teeth. 3-4 TPI for ripping "normal" sizes is about right. More teeth for thinner stock(otherwise each tooth just goes BANG as it hits the workpiece). Narrow blades for curvy stuff, the widest it will take for straight rip cuts.
BUT.
It is a small saw. Not a lot of power. But much more importantly, it won't be the most rigid machine ever built, and that matters. The blade - any blade - will only perform its best if it is tensioned properly. Just like pulling an elastic band, a wide, thick, blade is harder to tension properly than a narrow, thin one, and most small hobby saws are not rigid enough to tension wide blades properly, no matter if the wheels themselves are wide enough to take the blade. So you will get best results if you don't take the saw to its limits. Choose a blade of, say, 10mm wide, with 3tpi for ripping, with a thin kerf, and you should be able to tension that properly. And anything smaller, of course.
I have a big BS that copes with anything I throw at it, but for years I had a little Elu and did a lot with it. I wish I still had it, actually.
Get the right blade for the job, set it up properly and you will be smiling as you cut.
Just don't expect to pull a caravan with a mini.
Steve
PS Buy your blades from Tuffsaws, they are the best and not expensive. That's a rare animal, but in this case it really does exist. And it really does make a difference.