I found the opening post quite interesting and, as an agnostic (a theory of knowledge rather than a belief, which is atheism) I thought I would give a few responses to the arguments presented.
The two examples you give are not, I'm afraid, indicative of the existence of a God (you just found the polystyrene and the bug left...). There is no evidence to suggest that God caused the events, and thus I feel can dismiss it without evidence.
Then, you mention about "God's unconditional love for us" - I'm assuming that is unless your gay (Leviticus 20:13), do not believe in him (John 1:9-11) or are a woman (Timothy 2:11-15). You could quite rightly point out that such views are just a product of the time in which the bible was written; exactly, it's a product of the time it is written, not the work of a timeless God (who you suggest "never changes"), because it's a book of fiction, just as Macbeth was a product of early Stuart England.
"It doesn't matter how many times we mess up. He still loves us. I think that's pretty incredible" - I disagree. If the leader of your country decided whether or not you went to prison based on your submission to him, rather than your actions and intentions, you would quite justifiably say this is unjust. Why, then, is it okay for God to judge you based on your belief in him, rather than how 'good' your intentions and actions are? I would say that it is not "pretty incredible".
"looking at some of the things in nature (mountains in Wales for example) it's hard to believe that there is not some higher power due to how incredible nature is" - Without getting in to what how such arguments regarding the beauty of nature is can be explained scientifically, I don't think that nature is incredible. The "higher power" who designed Mount Snowden, for example, also, then, created Mount St Helen's, in the USA, which when it erupted in 1980 killed 57 people. God, therefore, exists, because he created our incredible nature, which kills us... Oh and he also unconditionally loves us...
If any Christians (or those of other monotheistic religions) are reading, I wonder if they could tell me how they would answer the following questions (some or all of which you may well have heard of and considered before): If God is all powerful (I'm assuming you think he is) then could he create a rock he could not lift? If God is also all knowing, then surely everything is predetermind, and thus why would he predetermine me not to believe in him? If God made us and wanted us to believe in him why do we believe in lots of Gods? What is it you find attractive about religion/ the existence of a God?