"Hey man, if you wanna run faster, just run more miles at a slow pace, that should speed you right up!" Is it just me or does that sound "illogical" if there is such a word? I'm a re-beginning runner myself as I only started running in Jan this year after a 12 year layoff. To me the logical thing to do would be, "if you want to run faster, run faster".
Another problem I have with all this advice you're getting is that almost everyone is trying to get you into races even though you mention that is NOT your objective. Although I must admit running competitively makes me run faster. If I ran 8k now I would struggle to do it under 45 mins on my own, but in a race I would do it in 41 mins.
I started running in Jan '93 and in Dec that year I was running 55 to 65 kms per week (10k x 4/5 + 15k long run). My 10k runs I did at 5 mpk (8 mpm). I didn't run a single race in that year and I did zero "speed training". I ran at a "comfortable enjoyable" pace and that pace kept increasing. So, if you just want to increase your speed for your current 25 mpw just increase your speed for each run a little bit, i.e. if you do 5 miles in 50 mins try doing it in 48 mins this week, 46 next week, or something like that.
Then we have to look at your other "problem", if I read your other posts correctly it looks like you do lots of weight training. I think that's where your 'problem' lies. If you have lots of muscle especially on the legs then your body is designed for sprinting not long distance. You have an overload of 'fast twitch' muscles and not enough 'slow twitch' to run 'fast' over distance (2 miles). If you want to run 2 miles in 13 mins you might have to cut back on the weight training.