Combat essentially breaks down (IMO) to an action economy, but unlike games like D&D, each action has a very realistic chance of backfiring on you and two of your 3 most precious resources (Edge and nuyen) are refiled at a variable rate. There are definite advantages to being able to go more often than your opponent, but you have to essentially budget for the extra Edge and bullet use that occurs when you do (this gets really bad when you have more IPs and 2 or 4 arms all taking actions separately by dividing dice pools).
If you're seriously worried about glitching when attacking to the point of banking extra edge for it, then something has gone horribly wrong either with your RNG or dice pool size. And even if you're shooting SnS out of a Supermach 100, that's only 96Y a pass. I know shadowrun pay is terrible, but it's not
that bad.
The problem is that offense is better than defense in SR especially if you don't use cyberlimb armor. Thus each IP is worth less since there's a good chance either you've already won, lost, or it's basically just a wrap up. After IP 3, you've fired 6 times (or cast 3 times). If the fight hasn't been decided by then, the next 2 shots or spell likely don't matter. Sure I'll take more IPs for free, but they cost more and more.
You do want a second IP. But a second IP is cheap (worst case buy cram). A third IP is quite nice and not that hard to get. The fourth is just too pricey. You do care a lot of initiative though so be sure to get that high as you reasonably afford.
Wired Reflexes aren't that bad. Wired Reflexes 2 eats up 3 points of essence, but if you're mundane you don't care. Unless you have widgetitis and load up on crud (a lot of ware isn't worth their nuyen price much less then essence cost), you can get everything you want with the 3 last points. You can make essence go a long way. Sure mages get Increase Reflexes and in some ways it's better since it increases initiative directly and thus stacks amazingly well.
There was a lot of hand wringing over wired reflexes in older editions. This was because your "IPs" and initiative were one and the same. So if you got a lot higher roll than everyone else, you could go multiple times before anyone else could act. So initiative boosters were a big deal and there was some optional rules to hose them (including a jumpiness roll that was made just so reaction triggers had an use). I recall it was harder for mages to buff their own initiative, but this was back in 2nd edition days so my memory is hazy on the subtle balances back then.
I must admit our group didn't catch the movement spread over multiple IP for everyone rule until quite recently. To be fair, we haven't really cared too much about movement (no map) and we all generally had 3 IPs.