Actually Improved Cargo Handling is useful. Reduces the load/unload times for your freighters, cargo ships and troop transports. Damage control is also very useful for in-combat repairs, or repairs post-battle to get to a repair base. Laser size reduction, I'd only use this on fighters or maybe a PD design. Laser warheads are broke if I recall, and I've never built an increased rad warhead.
Personally, I'd have improved cargo handling on the list of top economic techs. The faster you can turn around the ships, the faster your minerals/colonists get to where they need to be.
Well, when you compare
Improved Cargo Handling to the
Standard Variant you can see that it is twice as “strong” (i.e. each unit adds 10 “cargo handling” instead of 5 IIRC). However, at the same time it is 2.5 (IIRC) times more expensive in build points. So actually it is a bit cheaper to simply double the number of handling systems, rather than using more advanced versions. The only drawback is that this adds a bit more weight to the ship. Yet cargo handling systems only have a rather small mass in the first place and they are likely to be found on rather massive ships. So in the end I find the standard variant to be superior. But even if you don’t, there is at best a very small edge between 1 improved and 2 standard systems, hardly worth for a beginner to place on a high priority, if squeezed for research points. EDIT: Darn,
TheDeadlyShoe beat me to it, sorry I have just missed that. /EDIT
Post-battle repairs can usually be done just as well by engineering modules. True, it might take half a day instead of an hour, but in most post-battle situations that is not really much of a concern. That might change with the new upcoming overcrowding rules, as then you might actually have an incentive for leaving more quickly. But for now the marginal benefit hardly warrants the investment.
In-battle repairs are another story. It does matter tremendously how quickly repairs get down. However, even damage control is unlikely to push that time down to the point where it becomes truly useful (as in has an impact on the battle). So you need multiple damage control modules. And therein lies the crux, because ships cannot share their damage control rating, they are limited to a per-ship basis. Which again means damage control is something reserved for large ships. And in turn, large ships are something more likely to be seen in later game, when shipyards and maintenance facilities are available. So firstly its advisable to not make this a priority project, and secondly, while an interesting aspect of the game, it can also be ignored completely without much negative impact. Certainly, for a new player who is struggling to get his priority rights it is something to skip first.