You may be able to get away with just re-grading the landscaping on the outside of the house. You'll need a MINIMUM of 1/4" per foot (over a distance of 3' = 3/4") to get water away from the foundation. Then, once the water is 'diverted' 3' from the foundation, you need to get rid of it from there. Of course, if you can add MORE of an 'angle' to the landscaping AND add MORE than a 3' distance, you'll do much better and MAY not have to divert the water any further. If, on the other hand, you're on a fairly level lot and have packed clay soil, you may have to 'catch' the excess water and have it diverted further away from the foundation.
Now, what you want to do during the next HEAVY rain is put on your boots, raincoat, and get an umbrella. Step out into the storm (being mindful of lightening of course), and walk ALL the way around the house looking UP and DOWN to see where the water is coming AND going. IF you find your gutters are RUNNING OVER the top or are leaking at 'joints', or are not working properly, have that fixed too. The same goes for the downspouts. Be sure the water is being 'dumped' a MINIMUM of 3' from the foundation AND that the water isn't running BACK towards the foundation. And lastly, maybe there's a roof-line, or 2, where you DON'T have gutters and downspouts and need them. Have them added and make sure the 'function' as I've previously described. With all this working properly, you MAY not need to do ANYTHING on the inside of the basement. Waterproffing the walls is NOT meant for walls the kinda leak and have cracks and have water kind running through them. Eventually, pressure will push through the waterproffing. Besides, almost any new homeowner or Home Inspector will notice new waterproffing and 'sense' that something is up. Know what I'm saying? So, your best bet is to minimize/reduce/eliminate the sources of water (as I described), then, kinda 'allow' the remaining water to come in and 'catch it' to have it routed to the sump pump. Sump pumps are 'bad' as long as they work and as long as there's a battery backup. Homes are always built in some of the most in-opportune places so sump pumps are used all the time. You might want to have your cracks FILLED with an expansion cement. There are some tricks to this so contacting a Pro might be in order.
I always say: Sometimes, it costs $$$ to make $$$. Try not to take too many shortcuts because, again, some prospective home owners or Home Inspectors will see this and start to wonder if you've taken shortcuts in other 'unseen' places in and around the house. Leave the sump pump unless your 'fixes' end up taking care of the water in the basement completely. THEN, I'd still leave it. (At least it will have cobwebs on it and you can say it's not been used ...) My best to ya and hope this helps.