Unfortunately, no! Though it looks the same from the outside, the inner dimensions are different so your fountain pen would not work as a rollerball/ballpoint pen with our adapter.
You can just add funds to your pledge to get one or more pens. So if you wanted two titanium pens you could pledge £120 in the £60 reward.
Yes, the Nova is compatible with Pilot G2 Refills.
Unfortunately, no! Mont Blanc use their own special size which doesn't fit. There are plenty of excellent rollerballs in the Euro standard size that you can use, so please don't worry about this.
Don't see the answer to your question? Ask the project creator directly.