It's close to the end of the set now so you're not going to improve much by changing anything, but for the next reset follow these general rules...
2 usual ways to start are:
1) Use first 99 turns on building a few farms, a few ind and mainly CS. Then store turns. ie sit and wait for 18 hours, collect your 6 turn bonus then wait again until the next time bonus and maybe again. By this time, there will be turrets, food and possibly some expensive tech on the market. Depending on your strategy, waiting as long as possible to properly start developing your country can be advantageous when others don't really know what they're doing and price their units too low.
2) Come out of protection straight away to sell turrets or food.
It's not likely that, with 600 acres or less that you will be attacked. It's not really worth it for the attacker (unless maybe a tyranny). It's cheaper for someone to explore and build than attack you with 600 acres. Up to 800 acres is still fairly safe.
Build your bpt to a good level. This will depend on what size you intend to become. My preference is to spend early turns building up to my preferred bpt (around 85-100) as I usually play techer where it's important to spend as many turns teching as possible and I always aim to have around 15k acres or so. If you're playing an indy then it's not as important to get to your peak bpt as early. When you simplify things down to desired size only then there is a way of calculating an optimum bpt which gives the lowest turns needed to build 100% of your land. I'm sure someone has it handy somewhere - it does depend on government too.
Specialize...
Casher
Governments - Rep, Demo, Theo
Build mainly ent and res (stay to around a 55:45 ratio) with a few ind for 100% spies.
Buy (mainly) bus, res and mil techs
Farmer
Governments - Fascist, Demo
Build only farms with a few ind for 100% spies.
Buying tech... buy mainly agri
Indy - build only ind.
Governments - Commie
Buying tech... buy mainly ind and mil techs
Techer
Governments - Theo, Tyranny
Build mostly labs
The above are the usual governments and strategies you might use. You can use others but beware of each governments advantages and disadvantages. Don't try to think that you can do everything as you appear to have done here. Many players will switch strategy types... eg start as a farmer, change to a techer then in the endgame change to a military base reseller (MBR). Having a high bpt will enable you to spend the least turns possible making these changes.
You should consider which techs will benefit you most. If you attack for land then Military Strategy is of some use. If you don't, then it's useless. Others are less likely to attack with missiles if you don't attack for land so you wouldn't need to spend on SDI either.
Use
http://www.eestats.com to it's full potential by looking at past games to see market prices as well as searching for potential landgrab targets.
You may want to decide on whether you should go all-x (that is, all explore). If you do, you can concentrate your military purchases to (mostly) turrets. This will save on upkeep for jets. You can always explore to around 2k acres then decide whether to get jets then to make some grabs. It is possible to explore to 12k+.
Mainly though, specialize. The other stuff isn't as important.
Have fun.
caff