I think he definitely was during everything with Samantha, he had to travel all over Alaska and reach different cashpoints, he stopped going to them as soon as LE were sent to monitor cashpoints but i don't remember it ever being confirmed that he spotted LE at one, possibly was the case i haven't read about this case in ages. After that he didn't turn up again until Texas, he probably saved most of the withdrawn Alaska money went to somewhere like Las Vegas and splurged then travelled to Texas when he was running low because he knew they would look for information on a big spender locally and that's where he withdrew again then was caught. Just a guess i have no clue what he did, he was purposely frustratingly vague, his story was very interesting so you'd think his interviews would be too but he just mumbles and laughs and repeats himself for hours from what i remember.
He seemed to go dormant for months at a time though which makes you wonder about his self-control. I didn't consider this but i've mentioned serial killers as the person Keyes reminds me off but after discussing this he reminds me of my brother in-law more than anything. Hard worker, great father, everyone always thinks he's incredibly nice and normal but he has had extreme gambling issues and has been in and out of prison since he was 17 (he's 38 now) due to it. He has four kids with my sister and she told him she would leave him if he didn't stop drinking because he was always aggressive and beat her once while drunk. This was like 13 years ago and he hasn't beat her since, but what he does is mysteriously disappears for a day 2-3 times a year and it's clearly him having saved up money to drink and gamble with. Thankfully he's learned control to the point that he's able to heavily moderate it, that's what i think Israel has done seems like he had a genuine connection with his wife and/or son that he couldn't give up that's now making me somewhat reconsider the "i don't want my son to see my sexual crimes" part even though it's still nonsensical.
Not comparing my brother in-law to Israel Keyes i just think that's the reason i can really see Keyes as a heavy gambler.