weather or not this is a scam account or not, never gamble with credit. Essentially this is gambling, but not with your own money as you know very well that without collateral, you could easily pocket the funds and walk.
If i ever needed a loan of any size on here, i would offer physical colleteral (be it an iPad, silver bar, high end graphics card or laptop etc, or whatever else or a combination therof) for the value of the loan + 10 - 20% and cover shipping both ways. But never take out a loan to gamble with, you are never GUARANTEED future income, it is merely gambling. I invested in some GPUs knowing I could sell them if push came to shove, but i would never gamble with any form of loan or credit.
Steam accounts are easy to retrieve by showing proof of purchases to steam support no matter who you give the account to.
Seriously, do not invest with money you cannot afford to lose. If you are genuine, be so careful, you must take into account power costs, potential risk of equipment failure, security of your coins, and changes in the market. Do not invest what you don't have, as you will never be in a position to repay if it went south. Plus maturity and ROI of most hardware is long. Warranty being 90 days for most, which is less than the ROI time.
A good example of collateral is physical or if you own any valuable altcoins, from a valuable piece of jewelry you may own, to any high end hardware (physical collateral) if you can cover insured shipping both ways to a trusted escrow like psychoticboy.
If you have a high end phone, laptop, high end camera, jewelry, bonds you can transfer, or similar as an example that could be used as physical collateral. This acts as security for the lender for the loan. For a loan that high, if you can find a local lender on here with luck, you could for example transfer an asset into their name (car you own, etc) or a combination of the above suggestions. No one who is sane will loan that amount without a valid piece of collateral.
I know the cost of getting 'in' is high right now, but there are some promising alts like NEM that might be cheaper if you only have a small amount to invest, or buy a GPU like the nvidia 1070 - 1080 or AMD Vega 64 for a few hundred to dip your toe in the mining game, you can use the nicehash miner and get bitcoin as a result, and still have something that will keep some value.
Please, please do not let emotion get you suckered into investing blindly. Some guy recently sold his HOUSE, his roof over his head to buy bitcoin at the current prices, even if you profited the risk of gambling your SECURITY which will always be there is big, I don't care how much profit i COULD make, if i already have such security as a roof over my head that I own. In your case, gambling a £5k loan and being £5k in debt if it all goes south, i advice you don't do it even if you have collateral, even if you have a lender and you can both work out a deal, you are risking your collateral and the lender's time for a gamble which may or may not pay off.
Don't get greedy. I lost out on £50k by NOT gambling and selling many of my coins at £1k, but I still was £10+k in profit in this entire venture and I wasn't going to get greedy, ill admit I was wrong about the potentials for Bitcoin price this year, and instead moved to this house and set up a functional business, but at the current prices, the caution is recommended more so. I couldn't afford to lose £10k and had the potential to have enough for my dream home with my partner, so I walked and took the money which went towards the move. No regrets. You cannot afford to lose this £5k, so please don't do it.
And do not take investment advice based solely on emotion or logic, but a careful balance between the two, because go all logical like I did, i did not factor in the mania/emotional component that would drive the price up higher like it has despite Bitcoins lack of utility at the moment as a payment network (i have switched to another coin to transact with my clients due to high fees). So there is going to be a ceiling where investors 'run out' and without practical utility as a payment system, there will be a kind of upper price floor.
But also, do not let mania and trading take over your life, the endless stress of watching markets can create a form of apathy towards the world in general, not unlike gambling addiction or similar addiction. Think carefully before you invest, and whatever you decide to do, there are no mistakes in this world, in this life and incarnation, only free will. Stick by your decisions, whatever you chose to do, all I can do is offer my advice. If you get into this, spend £60 on a ledger hardware wallet and securely store your seed as its much more secure than just having a wallet on your PC, research your investment, ignore the mining calculators, they change faster than your daily underwear change.
And, have fun!