Two hands - did i play them wrong?

[rejack]

First $50+$5 rebuy tournament with 130 players in ladbrokes. 15 players left blinds are 1500/3000 and i have 11500, (which was 2nd smallest stack) chips left. Im in button and get A4s everybody fold to me so i decide to raise allin when there two pretty tight players in blinds, with 20000 and 35000 stack. Big blind called with JJ and i was out. Something i could do better?

Then other hand in 50k guaranteed tournament in ladbrokes with about 800 players, after 1½hour 400 players left blinds 200/400 and i have 2.8k chips, im moved to another table and get JJ in first hand at utg+1 and UTG, with 7000 chips makes it 1200 to go and i think this is my chance to get possible doubles, other way blinds are going to eat me soon. So i raise back allin only UTG call and show QQ and im out. Could i play this situation any better?

- Jack