The reason pubs deal with a single agent is because they dont want the hassle of being approached by everyone asking for a gig. The agents job is to provide bands/entertainers of the standard required by the pub with a repetoire that the customers of the pub will enjoy, making them stay longer and run up a bigger bar bill. Sometimes going direct to the management can piss them off (yet another person intruding on thier busy day asking to play) and if it doesnt then it can piss the agent off who usually books the pub.
To play your kind of music in the pubs mentioned here I would suggest going through an agent but before you are ready for that consider the following:
1. Hook up with another acoustic guitar player and singer. A thicker guitar sound (the sound of 2 guitars) and someone that you can swap harmonies with will make you sound A LOT better
2. If you dont know how to sing harmonies...learn.
3. Dont worry too much about your pitching and diction. Practice makes perfect and you have quite a tuneful voice already.
4. When you sing, stand up and project your voice from right down inside your abdomin/diaphragm. I have played in a lot of cover gigs in sg and overseas, the PA system is never as good as it should be and it's always difficult to get good monitoring. If you dont project your voice, singing loud and confidently, you will have trouble being heard in a mix. This can lead to pitch problems as well as giving the engineer the headache of trying to turn your mic up loud increasing the chance of feedback.
5. When you are ready, with a setlist of about 40 polished songs, you need a decent demo recording. The one you have posted isnt good enough. It's hard to hear you properly and there is a lot of noise in it (air con/computer fan?) Your demo will be your calling card so it has to be as good as you can afford. I suspect that the method you recorded your songs with this time contributed to the odd pitch problem. I listened to some of the songs a few times and even then was reluctant to comment on the qualities in your voice because I didnt really think I'd heard it properly.
6. Hang out at places like Wala/Balaclava/Muddys, listen to the kind of songs they are playing and take note of what the audience enjoys and waht they dont. You are playing for the customers, not yourself, a happy customer is one that comes back there again and spends hard earned cash on drinks. A rich pub owner is a happy pub owner and if you can contribute to that then you will neve rbe short of places to play!
You have a nice voice and are to be admired for having the drive and determination to put yourself out on the net for comment and criticism. That takes...ahem...big balls (pardon the expression but I'm sure you know what I mean) and having the guts to do it means you are already a good deal along the way to being successful..no guts, no glory!
When you are ready, contact an agent such as Toni Goh
http://www.greenroomsuite.com/ Hire a rehearsal studio and have him drop by to audition you. Dont do this before you are 110% ready though!
As for songs and singers to listen to I would recommend that you check out Bic Runga who sings and plays acoustic guitar, a lot like you (except original songs of course). Sheryl Crow always goes down well with the customers. Also there is a great CD where female australian artists have covered the songs of Neil and Tim Finn (Crowded House/ Split Enz) called 'She will have her way';
http://www.hmv.com.au/product/rockpop.asp?sku=996258
Well worth checking out.
Good luck and don't give up!