I'm afraid that I don't own an anaconda and so I cannot check, but just out of curiosity... what is the armour rating of the anaconda given its lower mass and what would be the rating on a Corvette? This is where I would nerf the Anaconda based on other stats and where Frontier might have too.
Easiest way to compare ships is with Coriolis then you can see how things balance out stats-wise. The most important thing to note regarding the Anaconda is its mass reduction doesn't affect the amount of armor it's capable of equipping... in fact, the mass doesn't affect the armor at all.
I love my fer-de-lance and as much as it frustrates me, I understand that to travel long distances I need to travel in a ship dedicated for this and not kitted out for combat. If I want more fuel, I have to give up an internal and if I want a bigger FSD then I should really be giving up a couple of weapon sizes to squeeze it in as I'd probably need a bigger power plant to power it too... And then the weight will go up and manoeuvrability will suffer and all of a sudden I've become a Python. This way we have a nice variety of ships, otherwise we just make them all perform the same but look different. And if I do want to do a little exploring in my fer-de-lance, I shouldn't be able to get it to Colonia at the same speed as an Asp Explorer.
I think the Fer-de-lance could definitely use a fuel upgrade- perhaps bumped to the next level at least so its overall range isn't as limited but it's jump-range stays the same. For a "medium-class combat ship" it's a bit hampered in this arena. I also agree there should be a tradeoff, and the example you gave is a good one.