Gaming by Prose - Fight Smart, Fight Fast

Absolutely, use whatever you'd like. I'm happy to help--I don't know if any of what I suggested would pan out in play, but it's worth trying.

I think it looks good--it will be interesting to see how everything plays out in testing. I like the idea that using a skill to enhance an attack allows you to roll again--that's an apt use of a skill. My question for that is if it always replaces the original roll, or if you can "roll twice and use either result." Both have merits.
If you always replace the roll, even if the second roll is less, it's more "chancey" to use a skill to enhance the roll, and more dramatic. If you can use either roll, the players may feel they're getting more mileage out of it. Both ways could be fun.

Or, and it just came to me, another idea is that all skills can be added on to rolls already from the start if they so choose; it is not a reroll or a replacement roll, it is a direct empowerment. That means a normal roll may not be worth rolling by itself, since the opponents or scenario may be require a little more creative options.

So, for example, I can roll 1d6 to attack a creature with a spell--or if I use my arcana skill along with that attack, I get a modifier, like 1d6+1? I think that works nicely. The only thing to think about is how often players will do that; if a normal roll isn't worth doing without the empowerment, players will add their skills to every roll.
Which is fine, actually, it just means that players need to be careful about how to choose their skills. If you want to make it so that players can't always add their skills, you could give them a set number of such uses per day, maybe equal to their attack stat or something.

I will want to encourage creative experimenting and tactical risks, so adding skills to every roll is good.

Only if it becomes unwieldy, or broken, will I take a look again into moderating it.

That sounds good. I think you'll get a lot of creative uses of that.

Alright then, preparing game ad.

How should I title it, since it will be a freeform piece? Any ideas?

For a game title, something catchy is always key. You want people to notice it and be eager to be involved. You might want to note something out the "sandbox" nature of it, too; a lot of people here like the collaborative story kind of game.

A little late (and haven't read everything, so I may be misinterpreting something here), but please don't use the Freeform tag if you have some kind of systematic mechanics behind the games, even if simplified ones. Freeform is Freeform. If you have a "light-rules" system, that still isn't Freeform. Use the Misc tag instead.

Hadn't thought of that. Freeform is basically collaborative narrative, then?

What about puttnig it under Homebrew?