Amongst these claims you give away too much money, it's worth remembering China spends/gives away a lot more(Several times) on foreign aid than the US, because it's generally considered an investment(Improves long term trading when nations are able to buy from you, improves investment opportunities with better stability in those nations, improves access to natural resources and so on). Though the US spends a lot more on foreign military bases.
All real growth requires investment, sure you can make the numbers look a lot better over a 1-5 year period with cuts but eventually they will impact growth through many issues you've mentioned. Homelessness, particularly amongst veterans is also one of the largest issues of poverty here in the UK, with places like Manchester home to thousands of homeless and there's lots of research & data that links the rise of this issue directly with social welfare cuts. Here, and in the US, our nations lose far, far, far(Orders of magnitudes) more money from tax evasion of big businesses than we do from benefits, welfare, or any fraud related to them(£34bn vs £1.3bn here in the UK), including to immigrants or refugees, so I'm sure you can see why many assume the reason the nation has put a man who points to pretty inexpensive issues or scapegoats minorities while simultaneously having a long history of business failures and refuses to release their tax returns, while commiting further to essentially opening tax loop holes, is "uneducated" (Personally I think it's more a symptom of people becoming disenfranchised with establishment politics).
Obviously, the much bigger issue here is that 30 of the worlds 60 odd tax havens are under British control, our government doesn't just avoid solving the issues, they actively engage in making sure they're maintained. The EU made big strides to start closing up international tax loop holes, so crooked politicians persuaded the public that what we needed was to get away from those pesky EU laws, while claiming we'd be all good by... becoming a tax haven(Literally the main plan from Farage & co was to somehow reduce corporate taxes further to bring more companies in, despite us already having the lowest in the G7)