The bounty hunters offer the possibility of specialized ships with over-sized weapon slots in relation to their sizes. If you want to avoid the bounty hunters altogether you can disable them during galaxy generation as they can be quite tough. If you still want the bounty hunters to be present but relatively harmless, then you can do the challenges they offer for respect, rez and specialists. Remember that if you are on friendly terms with them, they can occassionally enter engagements on your side when you go up against tough opponents.
For weapons I would recommend either beams or cannons together with missiles. You should get the desired category high enough so that you can use either the fusion beam or the particle cannon. Combine this with gravity missiles and if using beams, leech emitters to sap and slow your enemies to a complete halt. You can then order your ships to focus fire on the crippled target, tearing it apart quickly.
For armor, I would recommend you eventually maximize shields, armor and hull in that order because zombie critters will not break into your ships until you have a hole in the armor and missiles are the hardest to dodge and affect hull most, so having tough shields and armor helps most against those. Eventually you may also want to put some points into goons so that you can easier fight off zombie critters, boarders and repair the vessels faster.
Reactor and thrusters are also important. While the particle cannon and the missiles will not demand a lot from your reactor, the beams might. Fusion beams and leech emitters should be combined so that you can keep firing for a longer time. Faster ships will also last longer in firefights as they are not as prone to get hit as slower ships.
Avoid the use of more complex weaponry such as bombs, drones, mines, shuttles and stealth. You want all your ships to be as fast, heavy-hitting and durable as possible.
The ships you should attempt to obtain are ones that have mounts well suited for the type of weapons you have chosen. When I go Cannons I usually use turret-based ships so that I do not have to try and aim too much with the ships, while forward-mounts are generally good for beams which are easier to aim. Avoid the ships that use mines, drones and bombs. Bounty hunter ships are generally a bit better than UTA or CIV ships of the same hull size category.
Currently achievements are not affected by the use of mods. So if you do not mind then I would recommend that you get a mod that enables the use of more hangars. The game supports up to 8 hangars but the total number have been disabled due gameplay balancing and computer resource demands. Purists will not agree with this though.
You should always strive to outlevel the current star system you are in by at least 5 levels. If you are up against equal-level opponents or greater most of the time you are going to be defeated. Hard. Start each plot related quest with full levels of rez and goons so that you can rebuild your flotilla when your ships get destroyed. Between engagements always try to mine extra rez from friendly mining bases, and gather goons from battles where you are friendly with both the UTA and the CIVs. Buy lots of data using goons, buy goons using rez and mine rez from the friendly mining bases. Insane is a very unfair challenge and at times it can be a bit grindy. Hopefully this information will help.