I first bought into BTC in 2013 for $1,500 when the price was around $80 per coin-all I could afford at the time.
I lost it all about 1 year later when Mt Gox shut down, not being able to recover anything despite their 'claimant page'.
I then bought (a lot less) coins in 2018. When btrade.io got bought by Kraken recently, Kraken made a mistake with the 2FA migration, and I am unable to recover my account despite multiple attempts / contacting them. Fortunately, this time it was 'only' 0.7 BTC.
So you never filed a claim for Mt. Gox? No record of anything? Even if so, if the amounts are high enough (I don't know how many BTC we're talking about), you could still consider hiring a lawyer in Japan to lodge a protest with the trustee.
As for Kraken, have you spoken with a lawyer? At these prices, it might be worth it to have a lawyer at least send them a threatening letter. Especially if your btrade.io account was verified, that would be a slam dunk. They tend to ignore you and shuffle your queries through front line customer service reps until you actually represent an actual legal threat.
Do you think it's still worth investing at this stage?
Yes. A 10x from here is very possible.
If so, how best to go about this? Is it safest to buy coins from an exchange, then immediately transfer it into an offline wallet on my computer?
Probably, yes. Some will recommend P2P but for inexperienced newbies that's a great way to get scammed. Send your coins to cold storage and HODL.
Apologies if this comes across as a rant, last year hasn't been great, this year is looking the same, and I had way too much time to think about 'what if Mt Gox hadn't gone down'...
99% of people around here dream about the coins they used to own. It's a common theme with Bitcoiners. It's only natural since everyone spends or sells their coins at some point, and it seems to never stop going up.