Two great questions. You are pulling them together as one common theme, but here are my thoughts breaking each out:
1. RE the listing contract you have in place that goes a few more weeks --
Yes, you are contractually bound. But, you are unhappy. For whatever the reason, you just are not pleased. So: ask to be released. The worst that can happen is they say No. If that's the case you may want to then phone the office manager, tell them you are unhappy, and ask them to release you from the contract. Personally, I'm of the opinion that if someone isn't happy with me/us, in many cases I'd prefer to let them go their way rather than put up with the bad feelings they have and the possible bad publicity they may want to espouse in the marketplace because of their unhappiness. It's a two-way street. From the realtors' end, why continue to work with a seller that is not pleased with the process? Is it really worth it?
2/ RE selling on your own (i.e. "saving on the commission" and being able "to be more aggressive with the pricing".
Ya know, Realtors absolutely love FSBOs (for sale by owners). They are part of our bread and butter. Regional and National statistics all show us that 9 out of 10 homeowners who try to sell on their own end up hiring a realtor later to sell their home. It just doesn't make sense for 90% of home "buyers" to risk it on their own to seek out, and then buy without industry counsel, a major asset without a true professional's (i.e. Realtor's) assistance. One reason: it's not costing smart buyers out-of-pocket funds to use a Realtor -- to rely on the Realtor's knowledge base -- and to take advantage of the Realtor's negotiating skills and overall know-how of the ins and outs of the real estate business. Why? Because for nearly 100 years it has been the custom in our country to have "the seller" pay the commission. So, for buyers: it makes perfect sense to utilize the seemingly no-cost services of a professional. More than likely, the buyers who are only moments-away and days-away from being willing to sign contracts and buy their dream homes have by that time enlisted a realtor as their "buyer-broker" to act on their behalf. In other words, FSBOs are chasing after only 10% of the potential buyers. And it is not easy for a non-real estate person to weed through one of those 10 percenters who may surface to really ascertain whether they can make it to the closing table.
As in all professions, we in our industry have average realtors and great ones. I'm a believer that hiring a good one can oftentimes save a buyer up to 10% on a purchase, and earn a seller 10% more with optimum marketing skills and positioning and negotiating strategies. Together, that can be as much as a 20% financial savings difference -- well worth the "commission cost" of compensating them for their value.
In summary: leave your present realtor now or later if you are unhappy, but rethink selling on your own. Few who do really make out. Even if a sale materalizes, one will never know how much may have been left on the table. There is much less likelihood of that when you market to the broad buyer spectrum available through the professional real estate market.
I'm sure many others who read your question join me in extending you and many others in your situation very best wishes for a quick and optimum sale!