Good on you for finding some work. There isn't a boat load of work out there due to the weather so all work is good.
From the point of view of a small company owner that uses subbies here is what I see.
1. I prefer to hire in a climber and work the ground/manage the other staff/customer than climb myself and hire a groundie. That is my personal preference and some of that is because there are much better climbers out there than I am.
2. As it stands based on what you have said I see you as hired labour, not a groundie. Someone to drag brash, chip stuff, clean up, be the groundies/cutters bitch vs. someone to be the climbers man on the ground running the ropes, being his rescue climber or running a sub team on a big no climb job. It may sound harsh but like driving once you have the license (tickets) now you need to learn how the job site runs. There are loads of labourers available but only a few pro groundies.
As for wages, minimum wage for an 8 hour day is a few pence short of £50 (labourer). I can get basic climbers for £70 using my kit and climb anything climbers with arb vehicle, rigging gear, selection of saws and years of experience for £100+. At anything more than £70 I would expect you to work with a labourer without issue on say a no climb site clearance.
This is the grim north so southern wages are higher. There are also loads of small companies where I am all competing for the same jobs so day rates are no that high. I personally think all wages should be higher but firstly most customers see us as expensive gardeners so don't want to pay big for the job and secondly there are loads of people wanting odd day subbie work so as a company owner I have a choice of who I employ and when it comes to labourers cost is a massive factor.
Stick to your guns, you only need a few companies giving you regular work to be fully booked, do a good job (goes without saying). There is always something to do so don't be seen stood around doing nothing, that's the bosses job. Don't over sell yourself, a bad reputation will spread like wildfire and if you get hired as a groundie and can't run the ropes the boss and climber won't be impressed and people will soon find out you can't do what you say you can.
If anything does come in then I will give you a shout and a chance.
Kev