A screenshot and version # of the program would help, as those can uncover things that could be missed with just text descriptions.
This came situation came up while playing Keldon's R4tG program and was wondering if it was a bug or not. The way that worked is correct. The reason why people say "you put the world onto your tableau, then discard it" is to let it be known that you DO receive settles bonuses from using IPB to destroy worlds. Specifically, the III rebates since the wording on those always say "... you place a --- world".
I have 2 alien planets out already and I use Imperium Planet Buster to "takeover and destroy" an alien planet. In the program I didn't get the "first to 3 alien" goal though I expected to.
Since goals being claimed from the center are checked at the end of a phase, the 3rd card with ALIEN on it was on your tableau, but then discarded immediately. You then check your tableau, and you still only have 2 ALIEN cards on there.
However, I had rebel freedom fighters and I got 3 prestige from taking over and destroying a rebel planet (2 from buster, 1 from start world) so I'm assuming things happen as if you had played the card into your tableau.
The difference between this and the ALIEN example above is RFF gives you the PP as it's placed on your tableau (so it's part of those III bonuses that are kicking in). As mentioned, it works differently with goals since they're checked at the END of the phase, whereas you get the PP right away for destroying a REBEL military world with IPB + RFF.
I'm also assuming that once you get a first goal, you can't lose it (i.e. if I get the "first to have every power" due to playing R&D and I later discard R&D, i still get to keep the "first goal").That's correct. however, make sure you would've gotten the goal when you placed just R&D. NOT b/c you placed another dev, and discarded R&D from your tableau ot pay for that "another dev".
I want to say it's a bug...but just wanted to check