Idea #2 ... compare this to Helios and I'll choose which one to do :D

[Ihime]

"Sufficiently analyzed magic is indistinguishable from technology."

The thing is that I run by the broader definition of technology as any knowledge that expands the capabilities of the society. Therefore, magic is also a technology. It doesn't matter if you lift the water from the well using buckets & pulleys or you lift it using the East Spirit of Water Lifting. Just because it's not in the recognizable Earth form doesn't mean that it won't have the same effects on society.

You want to remove guns and keep people to bows and arrows? That won't work if someone invents the Wand-That-Goes-Bang-And-Kills-People (presumably invented by someone who is bad at naming things).

You want to keep people from having interior plumbing and central heating? That won't work if someone invents the Fireplace-That-Traps-Fire-Elementals or the Bucket-That-Empties-Itself or the Everfull-Tub-Of-Clean-Water.

Basically, if you answer "magic" to things, then you're going to end up with a technological society that happens to use different physics to pursue the same comforts, conveniences, weapons, and similar goals as Earth humans do.

Answering "magic" doesn't really work if it does not hold up to the scrutiny of all the characters asking "why?" and "how?" They have had tens of thousands of years to take the system apart, study it, and create useful applications for it. Consider, for example, if you say that "You can get to the other planet using magic."

Is it teleportation? If it's teleportation, then you should be able to apply the same techniques on a smaller scale to travel across the same planet. If not, why not? If so, why isn't this the dominant form of transportation? And do the reasons prevent it from being the dominant form apply to interplanetary travel? If it's a simple enough and above all reliable enough magic to do interplanetary travel on the sort of scales that we're considering here, then at the intraplanetary scale we're talking about an entire planet full of teleporters who use it for casual travel. The distances and uncertainties are so very much smaller.

Is it flying? If it's flying, then you should be able to apply the same techniques on a smaller scale and produce a society where flying is the norm, since it's reliable and accessible enough to do much larger travel. You would have all sorts of things defying gravity. Additionally, there are necessary secondary magics (a term that's really interchangeable with technologies) such as radiation shielding, life support, pressure containment, zero-gravity medicine, and everything needed to support spaceflight.

If, however, you take the "easy" way out and say that it works only for interplanetary travel, then it creates a hole that is difficult for the suspension of disbelief to bridge, at least for anyone with even a slightly analytical mind. This is the equivalent of suggesting that a society knows how to build moon rockets but not passenger aircraft. Or that someone knows how to do calculus but not addition.

Addendum: Steam and guns coexisted for several hundred years. I don't see the issue with "still use steam but have guns".

Addendum: The whole idea that primitive people "live in harmony" with their environment is bollocks made up during a period of revisionism. Not even animals "live in balance with nature." They are forced into certain behaviors and population numbers by resource starvation.