Got 14mm F2.5, need advice on buying another lens

I'm new to photography, recently joined the M43 system with Panasonic GX7 and the Lumix 14mm F2.5 lens. I take photos as a unprofessionally as a hobby.

I spent my recent holiday in China, went on a ferry and took a lot of photos:

http://www.dpreview.com/forums/post/55070474

I did lots of research on cameras and lenses, which helped me making the decision on GX7 and the 14mm prime lens, one of the advantages of prime lens I saw is that it makes you thinking about composition, and 14mm (28mm in 35mm term) is good for landscape and streets which I mostly shoot.

The more I shoot, the more I feel the limitation of my 14mm prime lens. Especially on the ferry with limited space, wide angle lens simply wasn't suitable in some situations. For example, when I took photos of people, I need to move closer which makes people looking distorted, also, taking photos of strangers and standing closely to them might not even be feasible.

Then I'm considering the Pana Leica 25mm F1.4 and Olympus 12-40mm Pro lens, they both cover the 25mm (50mm in 35mm term) focal length, which is said to be the human eye's focal length and very suitable for street photos. I did some researches and thinkings around my main concerns:

1. Convenience

Primes are smaller in general, but when you need different focal lengths, it can be more convenient overall with a zoom length, in terms of spaces occupied in camera bag and the need for switching lenses. In my case, having two or more prime lenses and switching frequently is WORTH than having one zoom lens that always on camera. This is only considering the sizes and usage. In this regard, I'm more towards the Pro zoom lens.

2. Prime vs Zoom

I know this is an old topic, many people say that primes (with same focal length, aperture, etc) are better than zooms, in terms of price, IQ, etc. I found this article:

http://robinwong.blogspot.com.au/2014/07/olympus-mzuiko-12-40mm-f28-pro-lens_6.html

which shows good IQ from the pro lens. So my questions are:

i) HOW MUCH better in term of IQ, when the pro zoom lens is at 14mm and 25mm, compared to my current 14mm F2.5 and the Leica 25mm F1.4?

ii) HOW MUCH worse is the Pro's F2.8 compared to Leica's F1.4? I guess this has to depend on the situation, I do sometimes shoot in low light conditions.

3. Compatibility

They are all MFT lenses, and none of them has Panasonic's in lens stabilization (is this true?) But I heard that Olympus lens performs better when mounted on Olympus bodies, is this true?

4. Alternatives

Basically I need a less-wide lens to fill the gap of wide-angle lens in some situations (no need for tele-lens at the moment), the two lenses above are just what I could think of, is there any alternatives I should give a consider?

Sorry for the lengthy post and thanks!

Update:

Here are a few real world scenarios where I feel my single prime lens is limited:

Either I need to walk closer or the lens need to have larger FL, also I need larger aperture to make the shutter faster so less prone to hand shake blur.

In this case I want some bokeh to blur the background and faster shutter. I was feeling nervous when standing that close, which means I also need longer focal length to be able to stand further away from the subject. Also I frequently switching between shooting people and landscape, so switching lenses especially in that crowded situation might not be a good idea.

I want to zoom closer in this case, to make that big bridge 'stick' bigger, but simply I can't walk closer in the river.