I can't say for sure about the steering lock - there may be a keyway that you can drill out to free the barrel. I recall seeing a thread somewhere on here talking about it.
Security:
I've looked into this too.
First issue is a suitable switch. There are plenty around, but getting one a reasonable size is not as easy as I first thought. Consider where to mount the switch first, then try and get one to fit. My idea was to fit it in place of the FI light - and resite the FI LED to the bracing piece on the left of the FI light holder. If you didn't already know, the FI LED is very small and the original lens is small enough to be resited in a few places. You may want to fabricate a bracket that uses the handlebar mount bolts to secure it.
Next issue is relatively easy - what to wire to where!
I decided the best way was to isolate the fuel pump and starter.
As the fuel pump was permanently connected to earth/chassis, and the clutch switch was also permanently earthed, then these could be used - either using a 2 pole switch, where both circuits were separate, or use a suitable diode to prevent any backflow of current.
So, in theory, a not too difficult fix.
I understand that the ignition switch as fitted to the 449's will fit in the FI LED hole, but I've not tried it as I wanted to be more complex.
Call me obtuse if you like.
I don't like having my lights on all the time when off road, although I do ride with lights on when using tarmac. One of the first things I did was to wire in a switch so that I could have the lights on when I wanted to. As easy job as everything is wired back down to earth/chassis. A simple break of a wire at the front and rear, a toggle switch to connect them up and to earth and the job was done. Thinking I was looking forward, the switch hole was drilled in the brace part of the FI LED mount, as mentioned above, so the LED could be resited there.
My real issue is that I cannot find a 3 position switch small enough to go in the FI LED hole, so I have lights and ignition on the key (everything switched to earth - easy!). There is a supplier of aftermarket Harley parts that may have a switch suitable, but it is low on my priority list to go and have a look - I'd rather be riding the bike than playing with it at the moment!!
Drop me a PM if you need any more detail on my thoughts on this.
Mike