In some cases it isn't the pen that is at fault. If a cartridge or converter has a bad seal where it attaches to the feed it will allow air to enter the system uncontrollably and so the pen will leak. Re-seating and if necessary replacing a stretched or damaged cartridge or converter can resolve this.

That's not really something worth worrying about. As long as you don't store it nib down, no ink will leak. And even if you do get ink to fall out, it'll just go into the cap

They don't leak, unless it's broken or an eyedropper (where you fill up the entire body with ink).

Leaking usually doesn't happen, but that is very dependent on the pen. I have had some pens that leak and I quickly got rid of them. I still get ink on my hands from inking and cleaning my pens, but I feel that's part of the fun.

That could be your ink! Look into some quick-drying inks, Noodler's has some. That should minimize your smear. I think there's something youtube videos for lefties to help them!

Beyond fast drying ink consider a finer nib. Less ink on the page dries more quickly. Also, paper makes a big difference. Midori paper absorbs ink well while still providing some sheen, while paper like Tomoe River is coated such that the ink will sit on the paper for a long time making smearing more likely.

It's wonderfully excessive. It gives you a bit of line variation without going all out on finding a flex nib. Highly recommended.