Dynamite is really worth it, but always carry a few HE packs too. At 8k, they're expensive, but you need the extra damage to punch through cyberdiscs and tanks. My counter to power armor dudes is a hammer blow in the back. Works well enough..
Back to moneys:
Workshops are a long term safe investment: You take 3 months to pay it off, but then you get $570k every month. It works well if you then reinvest that into more workshop and create exponential income. But right now, it doesn't really look like we have the "seed money" to start on a rum venture. Would be a good thing to do when/if we get some good money from looting though! Cover the cost of 'em brainers..
I think I'd sell some slave AIs first, then maybe a ship engine or two (always keep.. ~3-4 of 'em for the next crafts you might build). Chances are that besides a zeppelin, we won't be building much soon. We should find more AIs and engines while looting!
If that's still not enough to get us a hangar, then selling some nuclear fuel or plastasteel is doable too. Just make sure we have enough to fly the Bonny for a while (at least 100?) so we can catch the shipping! Once the hangar is built, we can figure out where to get the cash for the zeppelin (which is pretty cheap if I remember well). If we're lucky, we'll have caught some shipping in the meantime and already have the money.
It's better to sell a few things for the hangar, and then sell other stuff later if we need to (but hope we catch something), than to sell enough for the hangar and zeppelin both now, only to get some loot from a chance UFO but run out of nuclear fuel and have to buy some back.
In the meantime, it might be worth it to just keep the Bonny at anchor over swtizerland or something. Pretty central to europe so whoever is flying there should ping on the radar. Trying to catch something after you've noticed the graph is hard because it's probably already done and gone.
The best use of the graph for me is finding where I need to setup patrols, then keeping a craft there to catch the next thing. You can't do it for a day or so either, since there is usually a gap between UFOs. Patrolling immediately after one means you're probably in that gap and you likely won't see anything. You have to patrol for a long time. Ideally in a central location without moving. Being at anchor costs less fuel than zipping around, so changing waypoints all the time is not a good idea unless you are hoping to catch a UFO that went off-radar. Zeppelins don't use fuel when at anchor, which makes them awesome for long term patrols (and they have great radars too!).