Most of the skill changes are just shuffling proficiencies around. The major one you'll notice is that the various electronics operation skills (Computer, Sensors, Comms, Remote Ops) have been bundled into Electronics, while the hardware aspect of the old Electronics is done with Mecanical (for fixing up stuff) and in some cases Engineering (for design). Battledress is now gone as a separate skill - you just use Vacc Suit skill to operate that (higher levels of skill being needed, depending on the suit). Gun combat merges Shotgun with Slugs. Sciences are all now part of one "Science" skill instead of several separate ones. Each actual science is still a different specialisation, but it means that someone with Science (Astronomy) 2 essentially has Science (Philosophy) 0. If that bugs you, it's no trouble to change it back to Physical, Social, Space etc as in 1E. Athletics skill has been redefined and fills in more, e.g. Zero-G skill has been replaced with using Athletics (DEX). There's nothing that makes a character rolled up under 1E a problem for play under 2E, but you may need to rename some of their skills.
The Boon/Bane mechanic is easily explained and able to be added to 1E without changing much. Effectively, instead of endlessly adding and subtracting modifiers for things that help or hinder a task, add up all the plusses and the minuses, and whichever is more than the other imposes a boon or bane. The mechanic is to add an extra die to the task roll, and to discard the high roll if a bane is imposed, or the low roll if a boon is in effect. So it has NO effect on the range of numbers that can be rolled, but still helps or hinders.
There are still some issues with the rules (the dodge rule needs work; it gives no benefit for average DEX characters without Athletics (DEX) skill. One fix is to make shooting at a dodging character a Bane as well as applying their DM as a negative), but it's pretty much free of typos. The skill tables are much improved from 1E, although some of that may be applying 1E errata. Some nice improvements in the character design sequence, such as University/Military Academy and the Prisoner "career" for some bad events.
Ship design has been moved to 2E High Guard, but the core book still has most of the expected common ships and ship combat rules. For the most part you should be fine to use 1E ship design to tweak the 2E ships (swapping out Cargo for more Staterooms or more fuel tankage, adding turrets etc).