Yes, you can

just buy the Sins vanilla then buy Entrenchment, should be about $30 total

as for the pirates, the devs are working them out so they will hopefully be fine soon

Well I see Madix2009 that you are not aware of how the devs work here. I admit that many games are like that, but here in the world of Stardock/Ironclad its much different. The devs have many times listened and used many of our recommendations and complaints to make the game better and better. In fact we complained the pirates in Entrenchment were too weak so the devs in Diplomacy strengthened them. We then complained that they were too strong and they have acknowledged the issue and are currently working on it. Given their track record, I would bet good money on them coming through, but that is your decision. As to the buy of the original Sins and Entrenchment, IDK have not really looked into it, just knew that used to be the past solution. Will attempt to help more on this.

If the devs say they're actually going to do something about it, then they're going to do something about it. 

Anyways, he's right, the original game is missing from Impulse.  There's Trinity, Entrenchment, Diplomacy, and the Entrenchment/Diplomacy bundle, but not the stand-alone original game.

odd, you would think that Stardock would keep that up

may have to drop them a line about it

oh and if the pirates are the only thing worrying you, you can always turn them off and enjoy the rest of the game

as for the minidump issues, most of the time its due to the person either having out of date drivers for something or other

Want some evidence?  Take a look at the patch log history, or 1.18 in particular:

https://www.sinsofasolarempire.wikia.com/wiki/Patch_1.18

The wiki is actually incomplete and doesn't list every patch.  This game has been supported extremely well.  Patch 1.18 in particular was great because many of the changes were based on feedback on this very forum.