Which laptop should I buy for undergraduate engineering?

Hello,

I'm interested in buying a new laptop for my upcoming first year of engineering. It will mostly be used for typical web browsing, but will need to be able to efficiently run typical engineering programs (I'm not sure of the specific programs, but likely at least matlab and autocad). I don't intend to major in computer science and the university has a computer lab if there are some less common, more intensive programs that most engineers need to run, so I don't need over the top graphics or processing speed; however, I don't want to have to rely on the lab for daily use so they need to be adequate. Gaming is not a factor as I don't intend to run any complex games so I shouldn't need intense graphics or resolution beyond 1980x1080, especially if they will cut away at my battery life. I would also love to have a touch screen if possible.

My spec standards or minimums: i7 processor, 8GB RAM, SSD Hard Drive (At least 256GB), 13.3"-15.6" screen, <6lbs(ideally), touchscreen (if possible)

Price Range: Less than $2000, but ideally closer to $1000

My priorities: Battery Life, portability, durability, solid (but not excessive) performance, touch screen.

What I am curious is what else I should be looking into. Initially, I was looking at at some ultrabooks as they offer great battery life with seemingly sufficient performance and great versatility, but I was told that I may need a quad core processor by the Best Buy people and several articles. The best buy guys led me to an HP Omen gaming laptop which seems to meet all possible requirements, but receives subpar reviews and doesn't have the battery life that I'm looking for. I'd like to avoid gaming lines if possible as I would be spending more for the same build quality of consumer lines. Don't worry, I know not to trust the Best Buy guys as they're obviously just trying to sell me the most expensive machine, I just mentioned them because they turned me on to the fact that I may need some things that the ultrabooks can't provide. I've been looking at several business models, but they are generally much bulkier and do not offer the battery life or touch screen feature that I want.

...So I have two questions
1.) I know there is a big difference between dual core and quad core processors, but I just really don't know how often I would even use all four cores for my average/typical use as an undergraduate engineer. Does the typical engineering student need a quad core laptop?

2.) Is there really a large difference between the build quality of top-of-the-line consumer model and mid-grade business model laptops that would fall in the same price range? I need this laptop to last me all 4 years, so not only do I need something built with solid interior parts that wont likely fail and require expensive repairs, I would like to be able to easily fix minor complications (i.e. battery replacement).

Recommendations
Please give me some specific recommendations for ultrabooks or lightweight business laptops for typical use as an undergraduate engineer that meet my above criteria.
My Current Considerations:
HP Spectre x360- the laptop that I was set on buying until my trip to Best Buy (I love its battery life, unibody aluminium frame, and versatility as a 2-in-1. Really a big fan of the spectre and it gets great reviews, so if it can handle the workload, this is my current #1.
Dell XPS 13 or XPS 15- XPS 13 was my ultrabook runner up to the spectre; XPS 15 seems to be premium in just about every category that I mentioned, but it may be a bit out of my price range so I'd like to spend a little less if possible
Dell Precision m3800- I can currently get one on sale for $1600 on Dell site
HP Envy 15 touch- cheaper option if i want to assume a 2 year life (likely stretching 3 with good care) before buying a replacement for the total price of a single premium unit
Lenovo Thinkpad T450s- I customized a pretty sweet looking one (256GB SSD, Touchscreen, 1920x1080 resolution, i7 5600u processor, 8GB RAM, backlit keyboard) for just under $1500 so this is also a top option with the spectre.
HP Elitebook 840p G2 Touch
HP Zbook 14- I've seen some mixed reviews on this one which makes me question its build quality, but it seems great on paper
I'm open to any suggestions not listed here, these are just the ones that I've been considering.

Added Note: 4 of the 5 laptops that you can buy through the school for engineers run on i5 processors which makes me think that a quad core i7 is excessive, and leads me to believe that an ultrabook with a dual core i7 would be sufficient in terms of processing power.

I know this post is a novel, so don't feel like you have to analyze everything that I posted. Any tips, suggested requirements, or recommendations on which laptop to buy would be greatly appreciated. Thanks in advance!