If a block gets orphaned, it means another viable block was added to the chain while the miner was adding transactions to the orphan block, right? Does that mean the miner doesn't get neither the 25 coins nor the transaction fees? If so, what's the point of adding bigger transaction fees as a safeguard against having the block orphaned?
Miners don't add tx to a block after they find one.
Simplified mining process
1) Miners select tx from the memory pool for inclusion in a new block (the number, method, and criteria is up to the miner)
2) Miners construct a merkle tree from the tx in step #1
3) Miners create a block header with the merkle tree, prior block hash, version, timestamp, and nonce
4) Miner will hash the blockheader. If it is a solution go to step 5.
4a) Miner will increment nonce and go to step 4. If nonce range is exhausted go to step 4b
4b) Miner will modify another element in blockheader, reset nonce range back to 0 and go to step 4
5) Miner has found a block. They broadcast it to peers.
So once a miner finds a block they are done. All the work for deciding tx comes BEFORE solving a block.