Wrong entrances and exits in funnel

I've setup a goal with this URL (/compra/comprafinalizada|/pedido/presupuestofinalizado) (match type: Regular Expression).

I've the following steps (there is no one required):

/introduccion
/filtros
/pedido(/)? (index)?$
/compra(/)? (index)?$

I'm having a few issues I can explain (I'm attaching an image with the samples):

A) Entrances from the previous step URL. Why this entrances aren't included in the funnel starting from the previous step? (If the visit get to /filtros from /introduccion, should be in the funnel and not aside like an entrance).
B) Exits to the URL of the same step they visits are going out from. The exit URL is (correct me if I'm wrong) where they went after leaving the funnel. If it wasn't on my site it is marked as " (exit)". If they went from /filtros to /filtros (maybe refresh) it shouldn't be an exit, the visit is still in the funnel.
C) Exits to the URL of the next step. This should never be an exit. The visit is continuing the funnel to the next step!

What is going on?

I've been reading some information but it doesn't explain all my issues and, those it does, it says it's a reported issue but the posts are from 2010:

Funnel sample

Solution

What you are seeing in (C) are visitors who bailed out of your site (bounced) when arriving at /filtros (so they never came back).

In the second level, 224 /filtros visitors (218 from /introduction + 6 other sources on the left hand of second level) when they arrived at /filtros , did not leave and continued on to /pedido (29)

But (B) shows that 11 bounced and didn't complete goal.

If you look at the first level of the left hand side, 896: (entrance) : 894 : went to /introduction /introduction : 1 : went to /introduction (they probably refreshed the session or had multiple tabs)

Second level now: (entrance) : 5 : went straigt to /filtros skipping /introduction /introduction : 1 : started off at /introduction and went to /filtros

Does that makes sense?

Don't assume that visitors use one browser, and only one browser tab and are only one person (for example a router can have many users on it).

Here's also a good article that explains some of the oddities. http://www.lunametrics.com/blog/2010/08/18/mysterious-funnel-exits/

Edit:

A) Could it also be the referrer of dead session? For example if I leave my computer browser on /introduction to go an cook something in my kitchen and come back 30 minutes later Google Analytics considers that a new visit/session so when I click the link /filtros on the page open in my browser the pageload of /filtros downloads the ga.js script and it gathers the referrer (where i came from) and sees that I have been idle for 30 minutes thus considers I'm entering not actively following your funnel.

Why did you make such a funnel anyways? You put no restrictions. Why not just make a goal with a last step of /compra/?success=true or something like that?