1. There's a spoiler item that can drastically increase your speed, if you find it (or rather, "them"). That's a subject for the "Hints, Tips, and Spoilers" forum. Other than that, alternately running and then walking when your fatigue starts to add up will train up your Athletics skill, leading to higher base Speed after a few levels...meanwhile you inch along. Taking "The Steed" birthsign or Speed as a favored attribute can give you a small starting boost, but you're well past character creation. Eventually, you should move faster, and by late game, it shouldn't seem like a problem.
2. Reflect can be dealt with in several ways. Summoned assistants which use conventional forms of attack (scamps, skeletons, etc.) can do the job for you. Unless you're using the Morrowind Code Patch, you can use Absorb Health as a form of offense. In most cases, reflect chance is low enough that you can deal with it as long as you have some immunity to the form of attack you're using (a Dunmer throwing fire damage spells, a Nord casting Frost, an Argonian dealing Poison damage, etc.). Obviously, an Altmer will have serious problems with reflected spells.
As far as using magic against normal creatures goes, duration is a lot cheaper than magnitude. Have a long-duration poison or elemental damage spell crafted (it's dirt cheap), like 2-2 points for 6 seconds or longer. Cast and then backpedal while the spell eats away at them, or levitate out of reach. The first second of the spell costs full price and magicka, but there's a significant "discount" on the additional seconds, so you can do almost double the damage for the same energy expenditure. Touch spells cost less magicka than ranged, and if you can add in a small amount of Paralysis, that can turn the fight around VERY quickly. If combining effects into a single spell, put a spell from a school that you're good at on top, because that controls the casting difficulty.