Out of your list I recommend the Pilot CH 91.
It has the best cartridge out of those you listed. You can refill one infinitely and it has a large capacity, and due to its large opening good flow. The con-70 is the largest size converter on the market available.
Also, right now you have a good window for the CH91: Either buy one in the new colours, or the old ones. Unless you fancy a black pen, then it's almost moot. (Only almost, as the clip has changed a little, so even the black pen varies).
I have no experience with the Falcon, but am eyeing it too.
Next up I like the Carene, I think it's gorgeous, but I never came around to buying one.
Pilot and Waterman nibs are very smooth.
I suggest a look at Sailor (and their MF nibs, or maybe F if you really want to go for an F).
Gold vs steel... Neither is better, as you write with the tipping, which is a whole other material yet, and the smoothness of the tipping depends on the manufacturer as well as the softness of a nib.
However, the markup on gold nibs from Western pen companies is ridiculous, and given the choice I rather buy the cheaper pen with the more precious material than an expensive with less precious material (ie gold vs steel). This of course only applies on overall quality being good and design according to taste.
Oh and it depends also on liking heavier or lighter pens.
Depending in where you are, it can be a pain to acquire Cross stuff (carts & converters) and their carts are rather dingly.. (very small capacity, small opening, I think they have the potential to wear out easily).
"Self-fillers" are a thing.. I like my piston Pelikans, I also like aero Parkers, but I think c/c is the best system and would choose it always over any self-filling system.