1) Yes, the winner is still expected to provide the next challenge.
2) example name: 1715-mark_man-amazingcomeback where the number (1715) is the value of your entry - typically the $ balance remaining, but some challenges have special rules with penalties and/or multipliers.
You'll then find the file titled AR2_A_214_Counterbalance.1715-mark_man-amazingcomeback.lvl2 in your AR2 profilename subfolder, under the "levels" folder in your AR2 installation folder. Send me a PM, and attach the file to the PM....
3) I might have mistaken what you're asking:
I think you want someone else to make a level and send it to you, so you can post it as the winner of this challenge.
It's a little tricky because that may disqualify the person sending you the challenge from competing themselves, and we're so thin in numbers these days that it's a risky idea.
The usual option is to plead for the second place solution to take over the obligation to post the next challenge. Probably best to do this, this time.
Personally, I'd much rather see your entry included and available for all to see, than scare everyone away with the obligation to post the next challenge.
So if you do win, I'll ask second place to post the next challenge. If there are howls of protest, then I think I can build a follow on challenge.
I'm assuming the problem is not an inability to edit levels (looks like you've done this before), but a lack of either time to build or creative ideas?
I've attached a base grid of anchor points that another regular sent me when I first started making challenge levels. I find it saves a lot of time building things - the hardest part for me is still the "new idea".
Andrew's AREdit program is also still floating around the forums too - he used it to build the "Halloween" challenge that preceded this one.