Independent Pride welcome to the forum! May your interactions be full of positive and helpful responses ... or cat pictures ... or torps (if you are game enough to venture into that thread
Focusing on Pilot, Tactics, and Stealth is great, but too much Stealth strongly limits your encounters, resulting in lower XP (from destroying enemies).
Pilot is key - Tactics can be 60%-80% of your level and still be fine ... actually, after a while, you can neglect tactics and only bump the skill up when you start missing.
I haven't had that much trouble with exp. When stealth is your main skill, you level up at about 130% of the recommended level according to the tablebases in help. Spy and solar wars are easier and also more profitable. You don't get that many hostile encounters, but you still get loads of money with high tactics. In the worst case there are upgrades providing penalty for encounters.
It's not just about being a spy. High stealth is useful for torping from distance. Against my stealth characters enemy captains don't hit me with torps too often, because I have a huge stealth and fast ship. If they by any chance manage to close on me, I back away (again, huge stealth gives me a great chance to win the roll). And my tactics help me with efficient torping. If I, by any accident, run out of torps, the enemy ship is usually so smashed that I can just close to mid range and gun them to death, because they don't have guns to fight with and they don't have enough engines to close on me. I saw people mentioning that large alien ships have insane hulls, but that's not really a bother, since I want to destroy engines anyway and with huge stealth xeno are almost always encounterable only with rumors and null field generator. Also, huge stealth gives me a great advantage in escaping enemy ships when I don't want to battle them