Let me put it this way. So what you seem to be describing up there has (i) powerful engines (good for getaways from dangerous things such as explosions of other vessels or other vessels), (ii) capability of forcibly docking with other vessels (for SCIENCE! of...how to best forcibly dock with other vessels), with (iii) grappling arms to manipulate and taken in other objects in space (such as other vessels), and (iv) a big enough space to hold the necessary gear (including cargo hold, to store all the, err...scientific samples and equipment you pick up during your run-ins with other vessles) to host personnel (including military, because you have to protect the SCIENCE! from hostile, uhm, environments).
I am so sorry, I do not mean to offend in any way, shape or form. But I read the above and a science vessel is the last thing I think. What DOES pop into my head, however, is this:
pirate ship. Pirate ship. PIRATE SHIP!!!!
*squee*
Well, usual early exploration is indeed a little bit like pirating: you visit unknown territories and try to get your hands on everything you can to bring it home for further examination. Just think of Columbus, Marco Polo and the likes - the explorers going around the world, before we humans had a good idea of how our own planet actually looks like.
For Mass Effect storyline, building a ship that can carry enough "loot" and well armed personell is a very logical way of thinking: we were already collecting artifacts non-stop since ME1 and we are well aware that there are a lot of very hostile lifeforms in the universe. Even if you forget for a moment that there were turians trying to kill humans, then batarians trying to enslave people, some Yagh inbetween and finally the Reapers as the apex of the hostility, there is still an occasional tresher maw or varren that need some good killing.