Please let me know if you would have played these differently. (Results in white).

PokerStars Game #6311736525: Hold'em No Limit ($0.25/$0.50) - 2006/09/16 - 20:57:39 (ET)
Table 'Prokne III' 9-max Seat #7 is the button
Seat 1: Holland_Jon ($26.60 in chips)
Seat 2: The Jezus ($73.30 in chips)
Seat 3: Aquarius 75 ($46.50 in chips)
Seat 4: chas2148 ($44.40 in chips)
Seat 5: amazinmets73 ($74.85 in chips)
Seat 6: sexygolfer67 ($12.20 in chips)
Seat 7: aaronosu ($62.25 in chips)
Seat 8: Isabelle G ($23.35 in chips)
Seat 9: AlexAllen02 ($41 in chips)
Isabelle G: posts small blind $0.25
AlexAllen02: posts big blind $0.50
*** HOLE CARDS ***
Dealt to AlexAllen02 [4c 4h]
Holland_Jon: calls $0.50
The Jezus: folds
Aquarius 75: folds
chas2148: folds
amazinmets73: folds
sexygolfer67: calls $0.50
aaronosu: folds
Isabelle G: calls $0.25
AlexAllen02: checks
*** FLOP *** [4s 5c 2h]
Isabelle G: bets $0.50
AlexAllen02: calls $0.50
Holland_Jon: raises $1.50 to $2
sexygolfer67: calls $2
Isabelle G: folds
AlexAllen02: calls $1.50
*** TURN *** [4s 5c 2h] [Ks]
AlexAllen02: checks
Holland_Jon: bets $3
sexygolfer67: raises $3 to $6
AlexAllen02: calls $6
Holland_Jon: raises $6 to $12
sexygolfer67: calls $3.70 and is all-in
AlexAllen02: raises $13 to $25
Holland_Jon: calls $12.10 and is all-in
*** RIVER *** [4s 5c 2h Ks] [Jc]
*** SHOW DOWN ***
AlexAllen02: shows [4c 4h] (three of a kind, Fours)
Holland_Jon: shows [Ac 3c] (a straight, Ace to Five)
Holland_Jon collected $27.65 from side pot
sexygolfer67: mucks hand
Holland_Jon collected $35.75 from main pot



PokerStars Game #6311688624: Hold'em No Limit ($0.25/$0.50) - 2006/09/16 - 20:53:23 (ET)
Table 'Seppina II' 9-max Seat #7 is the button
Seat 2: Miggo ($47.45 in chips)
Seat 3: Tiny Monkey ($49.50 in chips)
Seat 4: DJ_MTC ($21.55 in chips)
Seat 5: Pejarox7620 ($21.90 in chips)
Seat 6: AMAZ1NG ($160.15 in chips)
Seat 7: scorpionfish ($43.25 in chips)
Seat 8: AlexAllen02 ($47.50 in chips)
Seat 9: KBalint ($59.10 in chips)
AlexAllen02: posts small blind $0.25
KBalint: posts big blind $0.50
USANAMACK: sits out
*** HOLE CARDS ***
Dealt to AlexAllen02 [Ah Kd]
Miggo: calls $0.50
Tiny Monkey: calls $0.50
DJ_MTC: folds
Pejarox7620: calls $0.50
AMAZ1NG: folds
scorpionfish: calls $0.50
AlexAllen02: calls $0.25
KBalint: raises $1.50 to $2
Miggo: calls $1.50
Tiny Monkey: calls $1.50
Pejarox7620: calls $1.50
scorpionfish: calls $1.50
AlexAllen02: calls $1.50
*** FLOP *** [Ks 4d 8c]
AlexAllen02: checks
KBalint: checks
Miggo: bets $3
Tiny Monkey: folds
Pejarox7620: folds
scorpionfish: folds
AlexAllen02: calls $3
KBalint: folds
*** TURN *** [Ks 4d 8c] [Kh]
AlexAllen02: checks
Miggo: bets $7
AlexAllen02: raises $8 to $15
Miggo: raises $27.45 to $42.45 and is all-in
AlexAllen02: calls $27.45
*** RIVER *** [Ks 4d 8c Kh] [6c]
*** SHOW DOWN ***
AlexAllen02: shows [Ah Kd] (three of a kind, Kings)
Miggo: shows [4h 4c] (a full house, Fours full of Kings)
Miggo collected $99.90 from pot



Results oriented question in white:

Could I have gotten away from these hands or is this just normal variance? I've been trying to be very careful in big pots like this, but I got stacked on both of these and am wondering if I would do the same thing again.
In the first one I just have trouble hitting my set and then giving someone credit for the unlikely A3 holding or a bigger set even though the betting fits that. AK also seems pretty likely here.
In the second one I was trying to just complete the SB with AK to hide it's value and I thought it was going to work great on this board. At this level I could easily see someone playing it this way with a K and a worse kicker.