There were three issues raised at the start of the summer that I haven't dealt with yet, and thought I'd offer some reflection.  It turned out that the people who wanted to work on these issues aren't around at the moment, so I might come back to these!

1. Making practice (at club and at home) really helpful in terms of improvement
   That would be a good thing to solve!  Well, in many ways I've tried to promote and model this over the last few years, so I will be brief here.
   I think most have us have come across some variation or other of the experiential learning cycle , which Kolb and colleagues have developed over many years, originally in connection with adult education.  A chess version of this might look like:
   
   

   PLAY	==>	REVIEW
   /\ /\		\/ \/
   STUDY/PRACTICE	<==	REPORT

   
   The idea is to learn from experience, and focus on what actually is holding you back, and not what you enjoy studying.  Simon Webb (and Ish) have provided good models for how to look at your own game and identify weaknesses; Rowson and Dvoretsky have provided some good ideas about how to study.
   It is possible to improve at chess just by playing, because of course each exchange of moves allows for your current thinking to be challenged, each game gives you new experience to interpret.  But playing without reflection might just rehearse bad habits...
   It's hard to talk in general terms: it's also not clear what it is reasonable to expect from your study.  If you're a tennis player and work on your backhand, you might reasonably expect to be able to play a few backhands in your next match.  But if you study IQP positions, you may not see one for months.
   
   
2. Too narrow an opening repertoire
   I wonder what sort of problem that is.  I would have thought for most of us, we could do with getting into a groove with our openings, getting to know them better.  So, I've been trying to get Brian to stick to one opening system as White and two as Black, so he can get familiar with and eventually expert in those formations.  I think he's doing well with White but keeps making it up as he goes along as Black.  You branch out later, once you've got something solid to base it on.  When you do branch out, you can take on related systems, similar formations, and broaden your expertise in that way.  It's a good goal to be able to play any opening well, any type of position well, but be realistic about what you want to take on as an amateur with limited study time.
   It's possible to play any opening at amateur level, I think, and play it well and with your own ideas.  There is the Tony Dempsey IQP repertoire:
   White:
   Scotch Four Knights' Game
   Tarrasch Variation vs. French
   Panov-Botvinnik vs. Caro-Kann
   Alapin vs. Sicilian
   Black:
   Swiss Defence vs. QGD (although the Tarrasch also makes sense to me: you get into it a lot earlier so you're more likely to end up playing it!)
   Petroff's Defence vs. 1.e4
   
   
3. Calculating all the tactics out (relying too much on intuition i.e. Laziness)
   The penalty for doing that is of course missing things and losing.  If that doesn't hurt enough to make you change your ways...
   As for a cure, perhaps take on sharp positions against a computer, when you will surely be punished for being lazy.  Dvoretsky recommended a couple of deeply-analysed games from John Nunn to be used for playing-out against an opponent, (see the Canon) but by all means pick positions from an anthology of games by your favourite attacking player. 
   A similar technique is: play a series of games against your computer in open games (1.e4 e5), and re-start the game after any oversights.  Aim to extend the average length of the games!